Dear Tuomas, Have you received any solution or figured out workaround for this issues? Our users are experiencing the same problem.
At-least you are receiving the missed conversation emails. We don't receive those.
Unified Presence is a nightmare. Teams & Skype Co-Existence mode needs improvement. Teams at the moment is not so reliable.
We have the same issue. We have configured Teams co-existence in Islands mode yet this issue is coming up for all Skype Online users. Unified Presence is not reliable apparently.