I have the same problem Tom has posted here.
I use Teams on my mobile phone and on my desktop. When I start working on my desktop and my phone is idle, my Teams status becomes "Away" even though I am actively working on my Desktop, sometimes even when am actively chatting in Teams on my Desktop.
Doing a "Reset Status' on my Desktop doesn't seem to solve the problem.
It is as-if the "Away" status from my phone (being idle) is taking precedence over my activity in Teams on my desktop.
Tried what Igor mentioned. Nice improvement, now I won't be bothered with teams notification on my mobile when am working on my desktop.
However, this does not resolve the problem of my Teams status becoming Away when am active on my desktop and my phone's idle.