Additional meeting and call-related features and issues within Microsoft Teams for business
Hello MichalMarhevka this is a very annoying problem. Before I join a meeting that someone else is running I start MSTeams on my PC and check that I can customise the background, two weeks ago I did this and it worked fine but Friday when I went to join a meeting I forgot to run my version first and when I joined the meeting the option was missing. after the meeting I ran my version on my PC and I was able to change the background. Well all I can suggest is run your version on your PC and see what happens ---- let me know