New Teams is keep popping up on screen while users is working on Outlook or other apps

We are having the same problem. Even just switching between other open applications and the Teams App opens in front of them

I have also been having this issue over the last few days, and like the OP I am in New Zealand. One additional symptom is that the Teams icon on the Taskbar shows a "new" badge, and flashes orange like it has a notification or popup dialogue box that needs my attention. Once I mouse focus on Teams there is no visible notification or popup that requires any action by me.

Update -- It seems that after signing out and signing back in, machines in my environment are being rolled back. I am not sure if Microsoft actually issued a rollback for Teams, but prior to signing out of of a few affected machines, they were:

• Client version 49/24021528616, 49/24021528611, or 49/24021528615
• Outlook presence was not working. Was unable to see Green/Red/Yellow status icon when user is put in To/CC field of an email -- call buttons were disabled in the contact card.
• The setting "Register the new Teams as the chat app for Microsoft 365 (requires restarting Microsoft 365 applications" was not available in the application
• Teams would still popup when launching O365 desktop apps.

After signing out and signing back in just Teams:

• Client version 49/24020205514. This is actually a lower number version, suggesting there was a rollback of some sort.
• Presence immediately works in Outlook without even having restarted Outlook (I left it open while Teams signed out and back in)
• Teams now showed the setting "Register the new Teams as the chat app for Microsoft 365 (requires restarting Microsoft 365 applications", and it was checked/enabled
• Teams no longer pops up when launching O365 desktop apps.

Other observance: It seems that rolling back to this version removed the "dark mode" appearance preference that was set on these machines. It was simple enough to reset that preference, though.

We actually started noticing this client version on Friday of last week (March 22).

I have seen no communication on a rollback from Microsoft myself, but it seems to be what I'm seeing. Time will tell if there is an update and if the problem resurfaces, though....

Same problem as noted above.

My solution: Uninstall Teams.

Look like we have two fixes for it.

1. Do a log out/login to new teams client.
   If this dose not solve it
2. Uninstall classic team (Old), and do the logout/login in new teams