The tricky part is to find the mentioned version 6.0.9329.1 as it is still not listed under the 5520/7420. I found it on Google: [URL] For some reason the 5520/7420 are are not in the compatibility list (yet) but it works like a charm. Thank you, arnevanhove 
Hello all, My company has been having serious issues with the Latitude 5520 models and MS Teams. When the user is in a one-on-one call in Teams, the audio works fine. Both parties can hear each other crystal clear. When another participant is added to make a group call, the Windows Audio service stops unexpectedly. This causes the user having the issues to be unable to hear, or be heard by, other participants of the call. This issue does not happen to other participants in the call. Checking the Event Viewer, the audio service does indeed halt. I opened services.msc and sure enough, the Windows Audio service was stopped. I restarted it and it started without issue. As soon as it started, the user could hear and be heard again. We have taken multiple methods of rectifying this issue: None of these have fixed the issue. Multiple users are now reporting similar issues, all of them using Latitude 5520s. Has anyone else run into these issues, and have you found any solutions? We are running out of ideas in our lab. Thank you!
Latitude 5520 and Microsoft Teams