Hello Robin,
You can up your count to at least four people. That's not the only interesting quirk I've noticed recently though.
When I want to switch folders, I have to hit enter twice on the new folder. So, for example, I want to check my junk folder. I move to the folders list, arrow down to junk, and I hit enter. Nothing happens. If i hit enter again it will open the folder. The same thing happens when I move to deleted items or back to my inbox or whereever.
I have two ideas worth checking on. Who with this problem has Teams installed? I can't speak for the switching to contacts issue because I just realized I have it, but the pressing enter twice on a folder began sometime after I installed teams last week. Second, microsoft says they release new features of Office 365 slowly to users. It is possible that those of us with this problem have a different build. What build number does everyone have? Mine is 16.0.14326.20404.