Once the server update for BAAS-12633 has been released, update the Sync Client connection to send the supported websocket protocol version list string sent in the Sec-WebSocket-Protocol field to use a different character instead of /, since a forward slash (/) is not supported by the websocket protocol spec and some custom websocket implementations may not work properly with the current format. The ClientImpl::Connection should also be updated to support parsing this new format in the websocket_connected_handler() callback function.

The current format of the strings is com.mongodb.realm-sync/# for PBS and com.mongodb.realm-query-sync/# for FLX, and an example new format could be com.mongodb.realm-sync-# for PBS and com.mongodb.realm-query-sync-# for FLX (where # is the supported protocol number).

Refer to BAAS-12633 for the actual character used for the protocol type and version delimiter. It could be - or #.

Once the server is updated, it will accept both the original format (with a /) and the new format - the reason for the change is because the / delimiter is not an allowed character for the Sec-WebSocket-Protocol field.