I can't re-log back in Microsoft account.

I wanted to play on my friends realm but when I tried log in it said "Unable to Connect" I watched different guides on how to fix it but most of the guides said to log out and re log in. So I do the exact same thing, but, then when I re-log back in it says "Oops! You are already connected to this account. Please use the previous account." I have tried everything but nothing. Please fix the bug.