Summary

When I upgraded to the MongoDB.Driver 3.0.0, I couldn't connect to the replica set cluster(ver: 8.0.1) I created locally using Docker. Upon discovering another user facing this issue and raising with your team, I implemented the suggested fix of specifying directConnection=true in the connection string.

This solved the issue locally. We use mongodb in our gitlab pipeline as part of our tests, and when running in our Linux gitlab runner, we get the error: 
"MongoDB.Driver.MongoNotPrimaryException : Server returned not primary error."

This issue doesn't occur locally with the same configuration.

Related issue: https://jira.mongodb.org/browse/CSHARP-5337

How to Reproduce

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Additional Background

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