Summary

The C# MongoDB driver has been working well up until v.3.1.0 in Unity (Dedicated Server for Linux build type).
Starting with v3.2.0, the MongoDB C# Driver started throwing, as soon as our server makes the first query, which is concerning, since sooner or later we'll have to update the driver.

The exception stacktrace.

We use MongoDB Atlas as the MongoDB server.

Have tried anything that is only imaginable, but wasn't able to fix this.
v3.1.0 is the last working version, this bug blocks us from updating to any newer C# driver versions, until it is fixed.

How to Reproduce

1. Install Unity (I use 6000.0.55f1).
2. Install MongoDB C# Driver for the Unity project, any version since 3.2.0 inclusive would work. Here is how I installed the driver: https://www.mongodb.com/community/forums/t/c-sharp-driver-in-unity/203747
3. Write any query, the one our server executes first (which is the one that throws), is 
_collection.ReplaceOneAsync().
4. Click "File" -> "Build Profiles", then select "Linux Server", then build and run it. Or just run from the Unity Editor by clicking "Play".
As soon as the query is performed, you will get the "ArgumentException: None of the discovered or specified addresses match the socket address family." exception.