Version 3.3.5 of mongodb driver does not select nearest mongodb server when readPreference is set to "nearest" and useUnifiedTopology is true.

Each query randomly chooses server from list of available servers regardless of its roundrip time. For example, my servers have roundtrip times of 10 ms, 160 ms and 190 ms and all of them gets selected randomly for query.

When useUnifiedTopology is set to false, everything works fine and nearest server with lowest latency is automatically selected.