!!! MANDATORY TO FILL OUT !!!
<!---

Questions: If you have questions about HOW TO USE Realm, ask on
StackOverflow,
or in our Swift Forum or Obj-C Forum.

Feature Request: Just fill in the first two sections below.

Bugs: To help you as fast as possible with an issue please describe your issue
and the steps you have taken to reproduce it in as many details as possible.

-->

Goals

Open Realm and sync

Expected Results

Open Realm and sync

Actual Results

asyncOpen never calls the completion handler

Steps for others to Reproduce

I recently had to terminate sync in the Realm UI and restart it. Since then, if I re-install my app and login, asyncOpen never returns. My code hasn't changed. It seems terminating sync is the problem.

Code Sample

        let config = TDRealmConfig.syncRealmConfiguration(for: realmApp!.currentUser!)
        RLMRealm.asyncOpen(with: config, callbackQueue: DispatchQueue.main) { (syncRealm, error) in
            if let error = error {
                self.uiConfiguration(with: .blank, message: nil)
                let message = "The database could not be opened: \(error.localizedDescription)"
                self.presentOKAlert(withTitle: "", message: message)
                
                TDAnalytics.shared.logEvent("SyncFailed", category: "Engineering", teamName: self.teamName, parameters: [analyticsErrorDescription : error.localizedDescription])
            } else if let syncRealm = syncRealm {
                self.realm = syncRealm
                self.checkForData()
            }
        }

Here is the logging info:
2021-04-12 11:12:11.215043-0700 Takedown[70560:11544351] Sync: Realm sync client ([realm-core-10.5.5], [realm-sync-10.0.0-beta.11])
2021-04-12 11:12:11.215179-0700 Takedown[70560:11544351] Sync: Supported protocol versions: 2-2
2021-04-12 11:12:11.215309-0700 Takedown[70560:11544351] Sync: Platform: iOS Darwin 20.3.0 Darwin Kernel Version 20.3.0: Thu Jan 21 00:07:06 PST 2021; root:xnu-7195.81.3~1/RELEASE_X86_64 x86_64
2021-04-12 11:12:11.215418-0700 Takedown[70560:11544351] Sync: Build mode: Release
2021-04-12 11:12:11.215537-0700 Takedown[70560:11544351] Sync: Config param: max_open_files = 256
2021-04-12 11:12:11.215659-0700 Takedown[70560:11544351] Sync: Config param: one_connection_per_session = 1
2021-04-12 11:12:11.215776-0700 Takedown[70560:11544351] Sync: Config param: connect_timeout = 120000 ms
2021-04-12 11:12:11.215903-0700 Takedown[70560:11544351] Sync: Config param: connection_linger_time = 30000 ms
2021-04-12 11:12:11.215989-0700 Takedown[70560:11544351] Sync: Config param: ping_keepalive_period = 60000 ms
2021-04-12 11:12:11.216113-0700 Takedown[70560:11544351] Sync: Config param: pong_keepalive_timeout = 120000 ms
2021-04-12 11:12:11.216270-0700 Takedown[70560:11544351] Sync: Config param: fast_reconnect_limit = 60000 ms
2021-04-12 11:12:11.216505-0700 Takedown[70560:11544351] Sync: Config param: disable_upload_compaction = 0
2021-04-12 11:12:11.216765-0700 Takedown[70560:11544351] Sync: Config param: tcp_no_delay = 0
2021-04-12 11:12:11.216991-0700 Takedown[70560:11544351] Sync: Config param: disable_sync_to_disk = 0
2021-04-12 11:12:11.217249-0700 Takedown[70560:11544351] Sync: User agent string: 'RealmSync/10.0.0-beta.11 (iOS Darwin 20.3.0 Darwin Kernel Version 20.3.0: Thu Jan 21 00:07:06 PST 2021; root:xnu-7195.81.3~1/RELEASE_X86_64 x86_64) RealmObjectiveC/10.7.2 takedown5-xbnrj'
2021-04-12 11:12:11.219343-0700 Takedown[70560:11544641] Sync: Connection[1]: WebSocket::Websocket()
2021-04-12 11:12:11.219655-0700 Takedown[70560:11544641] Sync: Connection[1]: Session[1]: Binding '/Users/9a/Library/Developer/CoreSimulator/Devices/40838E30-BD12-4502-9C60-67C6C21FD604/data/Containers/Data/Application/0053FA16-13EC-40ED-B687-751AA6BACBE9/Documents/mongodb-realm/takedown5-xbnrj/605fcfe30c0b904c076b6975/%22605fcfe59f1d81d9da21859c%22.realm' to '"605fcfe59f1d81d9da21859c"'
2021-04-12 11:12:11.219839-0700 Takedown[70560:11544641] Sync: Connection[1]: Session[1]: Activating
2021-04-12 11:12:11.220062-0700 Takedown[70560:11544641] Sync: Connection[1]: Session[1]: client_reset_config = false, Realm exists = true, async open = false, client reset = false
2021-04-12 11:12:11.220246-0700 Takedown[70560:11544641] Sync: Opening Realm file: /Users/9a/Library/Developer/CoreSimulator/Devices/40838E30-BD12-4502-9C60-67C6C21FD604/data/Containers/Data/Application/0053FA16-13EC-40ED-B687-751AA6BACBE9/Documents/mongodb-realm/takedown5-xbnrj/605fcfe30c0b904c076b6975/%22605fcfe59f1d81d9da21859c%22.realm
2021-04-12 11:12:11.221184-0700 Takedown[70560:11544641] Sync: Connection[1]: Session[1]: client_file_ident = 68, client_file_ident_salt = 636784584324775083
2021-04-12 11:12:11.221444-0700 Takedown[70560:11544641] Sync: Connection[1]: Session[1]: last_version_available = 2
2021-04-12 11:12:11.221582-0700 Takedown[70560:11544641] Sync: Connection[1]: Session[1]: progress_server_version = 0
2021-04-12 11:12:11.221749-0700 Takedown[70560:11544641] Sync: Connection[1]: Session[1]: progress_client_version = 0
2021-04-12 11:12:11.221914-0700 Takedown[70560:11544641] Sync: Using already open Realm file: /Users/9a/Library/Developer/CoreSimulator/Devices/40838E30-BD12-4502-9C60-67C6C21FD604/data/Containers/Data/Application/0053FA16-13EC-40ED-B687-751AA6BACBE9/Documents/mongodb-realm/takedown5-xbnrj/605fcfe30c0b904c076b6975/%22605fcfe59f1d81d9da21859c%22.realm
2021-04-12 11:12:11.222100-0700 Takedown[70560:11544641] Sync: Connection[1]: Session[1]: Progress handler called, downloaded = 0, downloadable(total) = 0, uploaded = 0, uploadable = 0, reliable_download_progress = 0, snapshot version = 2
2021-04-12 11:12:11.222285-0700 Takedown[70560:11544641] Sync: Connection[1]: Resolving 'ws.realm.mongodb.com:443'
2021-04-12 11:12:11.233452-0700 Takedown[70560:11544641] Sync: Connection[1]: Connecting to endpoint '54.202.198.109:443' (1/1)
2021-04-12 11:12:11.283839-0700 Takedown[70560:11544641] Sync: Connection[1]: Connected to endpoint '54.202.198.109:443' (from '10.0.1.125:50485')
2021-04-12 11:12:11.294755-0700 Takedown[70560:11544638] [] nw_protocol_get_quic_image_block_invoke dlopen libquic failed
2021-04-12 11:12:11.513342-0700 Takedown[70560:11544641] Sync: Using already open Realm file: /Users/9a/Library/Developer/CoreSimulator/Devices/40838E30-BD12-4502-9C60-67C6C21FD604/data/Containers/Data/Application/0053FA16-13EC-40ED-B687-751AA6BACBE9/Documents/mongodb-realm/takedown5-xbnrj/605fcfe30c0b904c076b6975/%22605fcfe59f1d81d9da21859c%22.realm
2021-04-12 11:12:11.513751-0700 Takedown[70560:11544641] Sync: Connection[1]: Session[1]: Progress handler called, downloaded = 0, downloadable(total) = 0, uploaded = 0, uploadable = 3298, reliable_download_progress = 0, snapshot version = 3
2021-04-12 11:12:11.513980-0700 Takedown[70560:11544641] Sync: Using already open Realm file: /Users/9a/Library/Developer/CoreSimulator/Devices/40838E30-BD12-4502-9C60-67C6C21FD604/data/Containers/Data/Application/0053FA16-13EC-40ED-B687-751AA6BACBE9/Documents/mongodb-realm/takedown5-xbnrj/605fcfe30c0b904c076b6975/%22605fcfe59f1d81d9da21859c%22.realm
2021-04-12 11:12:11.514287-0700 Takedown[70560:11544641] Sync: Connection[1]: Session[1]: Progress handler called, downloaded = 0, downloadable(total) = 0, uploaded = 0, uploadable = 3298, reliable_download_progress = 0, snapshot version = 3
2021-04-12 11:12:11.515744-0700 Takedown[70560:11544641] Sync: Using already open Realm file: /Users/9a/Library/Developer/CoreSimulator/Devices/40838E30-BD12-4502-9C60-67C6C21FD604/data/Containers/Data/Application/0053FA16-13EC-40ED-B687-751AA6BACBE9/Documents/mongodb-realm/takedown5-xbnrj/605fcfe30c0b904c076b6975/%22605fcfe59f1d81d9da21859c%22.realm
2021-04-12 11:12:11.515956-0700 Takedown[70560:11544641] Sync: Connection[1]: Session[1]: Progress handler called, downloaded = 0, downloadable(total) = 0, uploaded = 0, uploadable = 3298, reliable_download_progress = 0, snapshot version = 3
2021-04-12 11:12:11.576458-0700 Takedown[70560:11544641] Sync: Connection[1]: WebSocket::initiate_client_handshake()
2021-04-12 11:12:11.576759-0700 Takedown[70560:11544641] Sync: Connection[1]: HTTP request =
GET /api/client/v2.0/app/takedown5-xbnrj/realm-sync HTTP/1.1
Host: ws.realm.mongodb.com
Authorization: Bearer eyJhbGciOiJIUzI1NiIsInR5cCI6IkpXVCJ9.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.5hoVl1JbrfRD-4lc6m3OxtOzS6Ox4e-PZMVYSTmlJW4
Connection: Upgrade
Sec-WebSocket-Key: KrLJrstcLmFBk4RZhnLphw==
Sec-WebSocket-Protocol: com.mongodb.realm-sync/2
Sec-WebSocket-Version: 13
Upgrade: websocket
User-Agent: RealmSync/10.0.0-beta.11 (iOS Darwin 20.3.0 Darwin Kernel Version 20.3.0: Thu Jan 21 00:07:06 PST 2021; root:xnu-7195.81.3~1/RELEASE_X86_64 x86_64) RealmObjectiveC/10.7.2 takedown5-xbnrj
2021-04-12 11:12:11.692736-0700 Takedown[70560:11544641] Sync: Connection[1]: WebSocket::handle_http_response_received()
2021-04-12 11:12:11.692877-0700 Takedown[70560:11544641] Sync: Connection[1]: HTTP response = HTTP/1.1 401 Unauthorized
cache-control: no-cache, no-store, must-revalidate
connection: close
content-length: 190
content-type: application/json
date: Mon, 12 Apr 2021 18:12:11 GMT
server: envoy
vary: Origin
x-envoy-max-retries: 0
x-frame-options: DENY
2021-04-12 11:12:11.693040-0700 Takedown[70560:11544641] Sync: Connection[1]: Websocket: Expected HTTP response 101 Switching Protocols, but received:
HTTP/1.1 401 Unauthorized
cache-control: no-cache, no-store, must-revalidate
connection: close
content-length: 190
content-type: application/json
date: Mon, 12 Apr 2021 18:12:11 GMT
server: envoy
vary: Origin
x-envoy-max-retries: 0
x-frame-options: DENY
2021-04-12 11:12:11.693174-0700 Takedown[70560:11544641] Sync: Connection[1]: Connection closed due to error
2021-04-12 11:12:11.693934-0700 Takedown[70560:11544641] Sync: Connection[1]: Allowing reconnection in 3524730 milliseconds
2021-04-12 11:12:11.710854-0700 Takedown[70560:11544351] [Harpy]: Please make sure that you have set _presentationViewController before calling checkVersion, checkVersionDaily, or checkVersionWeekly.
2021-04-12 11:12:12.621733-0700 Takedown[70560:11544641] Sync: Connection[1]: Canceling reconnect delay
2021-04-12 11:12:12.621902-0700 Takedown[70560:11544641] Sync: Connection[1]: Resolving 'ws.realm.mongodb.com:443'
2021-04-12 11:12:12.623254-0700 Takedown[70560:11544641] Sync: Connection[1]: Connecting to endpoint '54.202.198.109:443' (1/1)
2021-04-12 11:12:12.744577-0700 Takedown[70560:11544641] Sync: Connection[1]: Connected to endpoint '54.202.198.109:443' (from '10.0.1.125:50494')
2021-04-12 11:12:13.026578-0700 Takedown[70560:11544641] Sync: Connection[1]: WebSocket::initiate_client_handshake()
2021-04-12 11:12:13.026919-0700 Takedown[70560:11544641] Sync: Connection[1]: HTTP request =
GET /api/client/v2.0/app/takedown5-xbnrj/realm-sync HTTP/1.1
Host: ws.realm.mongodb.com
Authorization: Bearer eyJhbGciOiJIUzI1NiIsInR5cCI6IkpXVCJ9.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.PVCeqW1Z8Vo6idaq9g-3xphnQgMB5Tdlv_uh25r9WHs
Connection: Upgrade
Sec-WebSocket-Key: OKJw6CXImnOo0e4yGfPCfA==
Sec-WebSocket-Protocol: com.mongodb.realm-sync/2
Sec-WebSocket-Version: 13
Upgrade: websocket
User-Agent: RealmSync/10.0.0-beta.11 (iOS Darwin 20.3.0 Darwin Kernel Version 20.3.0: Thu Jan 21 00:07:06 PST 2021; root:xnu-7195.81.3~1/RELEASE_X86_64 x86_64) RealmObjectiveC/10.7.2 takedown5-xbnrj
2021-04-12 11:12:13.117132-0700 Takedown[70560:11544641] Sync: Connection[1]: WebSocket::handle_http_response_received()
2021-04-12 11:12:13.117365-0700 Takedown[70560:11544641] Sync: Connection[1]: HTTP response = HTTP/1.1 101 Switching Protocols
cache-control: no-cache, no-store, must-revalidate
connection: Upgrade
date: Mon, 12 Apr 2021 18:12:13 GMT
sec-websocket-accept: DxakIi5Lg7u5Vk2Qem5Pgci+td8=
sec-websocket-protocol: com.mongodb.realm-sync/2
server: envoy
upgrade: websocket
vary: Origin
x-frame-options: DENY
2021-04-12 11:12:13.117543-0700 Takedown[70560:11544641] Sync: Connection[1]: Negotiated protocol version: 2
2021-04-12 11:12:13.117868-0700 Takedown[70560:11544641] Sync: Connection[1]: Will emit a ping in 39916 milliseconds
2021-04-12 11:12:13.118185-0700 Takedown[70560:11544641] Sync: Connection[1]: Session[1]: Sending: BIND(path='"605fcfe59f1d81d9da21859c"', signed_user_token_size=857, need_client_file_ident=0, is_subserver=0)
2021-04-12 11:12:13.118420-0700 Takedown[70560:11544641] Sync: Connection[1]: Session[1]: Sending: IDENT(client_file_ident=68, client_file_ident_salt=636784584324775083, scan_server_version=0, scan_client_version=0, latest_server_version=0, latest_server_version_salt=0)
2021-04-12 11:12:13.118583-0700 Takedown[70560:11544641] Sync: Connection[1]: Session[1]: Sending: MARK(request_ident=1)
2021-04-12 11:12:27.101871-0700 Takedown[70560:11544351] Configure realm with team id = 605fcfe59f1d81d9da21859c
2021-04-12 11:12:27.102481-0700 Takedown[70560:11544641] Sync: Connection[1]: Session[1]: Sending: MARK(request_ident=2)
2021-04-12 11:12:53.037583-0700 Takedown[70560:11544641] Sync: Connection[1]: Sending: PING(timestamp=1650256050, rtt=0)
2021-04-12 11:14:53.042686-0700 Takedown[70560:11544641] Sync: Connection[1]: Timeout on reception of PONG message
2021-04-12 11:14:53.042925-0700 Takedown[70560:11544641] Sync: Connection[1]: Connection closed due to error
2021-04-12 11:14:53.043293-0700 Takedown[70560:11544641] Sync: Connection[1]: Resolving 'ws.realm.mongodb.com:443'
2021-04-12 11:14:53.045046-0700 Takedown[70560:11544641] Sync: Connection[1]: Connecting to endpoint '54.202.198.109:443' (1/1)
2021-04-12 11:14:53.089269-0700 Takedown[70560:11544641] Sync: Connection[1]: Connected to endpoint '54.202.198.109:443' (from '10.0.1.125:50561')
2021-04-12 11:14:53.249820-0700 Takedown[70560:11544641] Sync: Connection[1]: WebSocket::initiate_client_handshake()
2021-04-12 11:14:53.250202-0700 Takedown[70560:11544641] Sync: Connection[1]: HTTP request =
GET /api/client/v2.0/app/takedown5-xbnrj/realm-sync HTTP/1.1
Host: ws.realm.mongodb.com
Authorization: Bearer eyJhbGciOiJIUzI1NiIsInR5cCI6IkpXVCJ9.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.PVCeqW1Z8Vo6idaq9g-3xphnQgMB5Tdlv_uh25r9WHs
Connection: Upgrade
Sec-WebSocket-Key: YNo6xGqm/XcXK7WmlucpMg==
Sec-WebSocket-Protocol: com.mongodb.realm-sync/2
Sec-WebSocket-Version: 13
Upgrade: websocket
User-Agent: RealmSync/10.0.0-beta.11 (iOS Darwin 20.3.0 Darwin Kernel Version 20.3.0: Thu Jan 21 00:07:06 PST 2021; root:xnu-7195.81.3~1/RELEASE_X86_64 x86_64) RealmObjectiveC/10.7.2 takedown5-xbnrj
2021-04-12 11:14:53.349548-0700 Takedown[70560:11544641] Sync: Connection[1]: WebSocket::handle_http_response_received()
2021-04-12 11:14:53.349766-0700 Takedown[70560:11544641] Sync: Connection[1]: HTTP response = HTTP/1.1 101 Switching Protocols
cache-control: no-cache, no-store, must-revalidate
connection: Upgrade
date: Mon, 12 Apr 2021 18:14:53 GMT
sec-websocket-accept: eX5nDP0XJr/yIlMVMzcqWvWCby0=
sec-websocket-protocol: com.mongodb.realm-sync/2
server: envoy
upgrade: websocket
vary: Origin
x-frame-options: DENY
2021-04-12 11:14:53.349938-0700 Takedown[70560:11544641] Sync: Connection[1]: Negotiated protocol version: 2
2021-04-12 11:14:53.350088-0700 Takedown[70560:11544641] Sync: Connection[1]: Will emit a ping in 32671 milliseconds
2021-04-12 11:14:53.350259-0700 Takedown[70560:11544641] Sync: Connection[1]: Session[1]: Sending: BIND(path='"605fcfe59f1d81d9da21859c"', signed_user_token_size=857, need_client_file_ident=0, is_subserver=0)
2021-04-12 11:14:53.350496-0700 Takedown[70560:11544641] Sync: Connection[1]: Session[1]: Sending: IDENT(client_file_ident=68, client_file_ident_salt=636784584324775083, scan_server_version=0, scan_client_version=0, latest_server_version=0, latest_server_version_salt=0)
2021-04-12 11:14:53.350627-0700 Takedown[70560:11544641] Sync: Connection[1]: Session[1]: Sending: MARK(request_ident=3)
2021-04-12 11:15:26.024353-0700 Takedown[70560:11544641] Sync: Connection[1]: Sending: PING(timestamp=1650409036, rtt=0)
2021-04-12 11:17:26.029303-0700 Takedown[70560:11544641] Sync: Connection[1]: Timeout on reception of PONG message
2021-04-12 11:17:26.029641-0700 Takedown[70560:11544641] Sync: Connection[1]: Connection closed due to error
2021-04-12 11:17:26.030331-0700 Takedown[70560:11544641] Sync: Connection[1]: Resolving 'ws.realm.mongodb.com:443'
2021-04-12 11:17:26.032276-0700 Takedown[70560:11544641] Sync: Connection[1]: Connecting to endpoint '54.202.198.109:443' (1/1)
2021-04-12 11:17:26.072202-0700 Takedown[70560:11544641] Sync: Connection[1]: Connected to endpoint '54.202.198.109:443' (from '10.0.1.125:50646')
2021-04-12 11:17:26.222512-0700 Takedown[70560:11544641] Sync: Connection[1]: WebSocket::initiate_client_handshake()
2021-04-12 11:17:26.222785-0700 Takedown[70560:11544641] Sync: Connection[1]: HTTP request =
GET /api/client/v2.0/app/takedown5-xbnrj/realm-sync HTTP/1.1
Host: ws.realm.mongodb.com
Authorization: Bearer eyJhbGciOiJIUzI1NiIsInR5cCI6IkpXVCJ9.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.PVCeqW1Z8Vo6idaq9g-3xphnQgMB5Tdlv_uh25r9WHs
Connection: Upgrade
Sec-WebSocket-Key: XWWR28LtU3pggjw5tUBTZg==
Sec-WebSocket-Protocol: com.mongodb.realm-sync/2
Sec-WebSocket-Version: 13
Upgrade: websocket
User-Agent: RealmSync/10.0.0-beta.11 (iOS Darwin 20.3.0 Darwin Kernel Version 20.3.0: Thu Jan 21 00:07:06 PST 2021; root:xnu-7195.81.3~1/RELEASE_X86_64 x86_64) RealmObjectiveC/10.7.2 takedown5-xbnrj
2021-04-12 11:17:26.338458-0700 Takedown[70560:11544641] Sync: Connection[1]: WebSocket::handle_http_response_received()
2021-04-12 11:17:26.338683-0700 Takedown[70560:11544641] Sync: Connection[1]: HTTP response = HTTP/1.1 101 Switching Protocols
cache-control: no-cache, no-store, must-revalidate
connection: Upgrade
date: Mon, 12 Apr 2021 18:17:26 GMT
sec-websocket-accept: 3Z86FH2xpV60m2AqDFc+kxm1biM=
sec-websocket-protocol: com.mongodb.realm-sync/2
server: envoy
upgrade: websocket
vary: Origin
x-frame-options: DENY
2021-04-12 11:17:26.338843-0700 Takedown[70560:11544641] Sync: Connection[1]: Negotiated protocol version: 2
2021-04-12 11:17:26.339055-0700 Takedown[70560:11544641] Sync: Connection[1]: Will emit a ping in 18905 milliseconds
2021-04-12 11:17:26.339205-0700 Takedown[70560:11544641] Sync: Connection[1]: Session[1]: Sending: BIND(path='"605fcfe59f1d81d9da21859c"', signed_user_token_size=857, need_client_file_ident=0, is_subserver=0)
2021-04-12 11:17:26.339452-0700 Takedown[70560:11544641] Sync: Connection[1]: Session[1]: Sending: IDENT(client_file_ident=68, client_file_ident_salt=636784584324775083, scan_server_version=0, scan_client_version=0, latest_server_version=0, latest_server_version_salt=0)
2021-04-12 11:17:26.339632-0700 Takedown[70560:11544641] Sync: Connection[1]: Session[1]: Sending: MARK(request_ident=4)
2021-04-12 11:17:45.248767-0700 Takedown[70560:11544641] Sync: Connection[1]: Sending: PING(timestamp=1650548259, rtt=0)

Here are the logs from Realm UI:

Version of Realm and Tooling

Realm framework version: ?
10.7.2
Realm Object Server version: ?
4.4?
Xcode version: ?
12.4
iOS/OSX version: ?
14.2
Dependency manager + version: ?
Cocoapods 1.10.1