Additional features, settings, or issues not covered by specific Microsoft Teams categories
I have found that the PREVIEW updates for .NET 3.5 and 4.8 have been troublesome for Office apps (Excel, Outlook and Teams in my experience).
For example, one of my user's Outlook would crash when opening a Teams meeting from their Outlook calendar. I removed the preview update at the time for 1909 but I had another user on Windows 10 version 2004 and the resolution was the same.
Please verify you do not have any .NET PREVIEW updates installed by going to your Update History in Settings and checking under the Other Updates section . Open your Installed Updates from the Control Panel, find the KB and uninstall it if you found one.
The Cumulative Updates for .NET have not caused any issues so far but I wouldn't completely rule one out. In fact, they should fix the issues that its previous preview update introduced.
In conclusion, I was having the same issue with my Lenovo Thinkpad P43s on a Lenovo Dock Thunderbolt Gen 3. Workaround was to plug Ethernet cable directly to laptop's Ethernet port. I uninstalled a .NET preview update that sneaked in via MS Online updates and so far my meetings have not dropped.
I have another user I need to test this out with and will let you know the result.