Hello Anders, my name is Farah and I'm an Independent Adviser. I can help you regarding this problem
Have you tried disabling auto login from your profile in teams?
Click on your picture in Teams, go to Settings/ General / disable Auto-start application
If it didn't help,
Open System Preferences in Mac, go to Users & Groups, choose your name and choose Login items tab. check startup programs you want to remove.
Feel free to ask back any questions and let us know how it goes.
Cheers!
Farah