I've tried the solution here
but it still doesn't work. I've turned off all the notifications I can in Teams. Every time something happens in Teams - it could be something I have zero interest in, or something I can perfectly well attend to when I take a break and check email etc - that Teams taskbar icon starts flashing.
It's making it impossible to get any work done. Am I going to have to just put a piece of gaffer tape over the screen?