Additional meeting and call-related features and issues within Microsoft Teams for business
The funny thing is: I have no problems whatsoever to share Keynote presentations on both my Macs. The (really great) "play presentation in a window"feature also worked from the very first day. So I didn't realize this bug exists until I got a support call today from a teacher.
Given that sharing works for me but not for others, Microsoft can't just put the blame on Apple, this is clearly a silly bug in Teams which has been waiting for a fix for months now. Perhaps MS should just add someone with a clue to their developer team in charge of Teams for macOS…