It only happens on the Teams app for android. When you select accounts, you get a list, with the name of the org and the email account under it e.g.
ABC College
soandso at abccollege
So if I have my account (I work in a government school) and the other 3 are from 2 different colleges, apart of the 4 accounts, I have my email address on the ABC College (which I don't work in), my daughter's email on my sons' college (which she doesn't attend) and my son's email on my organisation (which he doesn't attend).
I have been using multiple accounts on Teams app for android without problems. This happened only this week. The biggest problem is that if I get a login page for one of the pseudo accounts, the whole app fails. I would need to delete cache, data etc as there's no way to remove accounts on android without signing out.
I have already followed an old thread and removed all accounts from settings, changed passwords, restarted the mobile, airplane mode etc.