Office keeps using another account when I reboot my computer

Question

Hi. This issue has been bugging me for months and I really want to put an end to this. I hope posting here can help me fix that once and for all.

So I've got a lot of microsoft accounts signed into my desktop. Notabilly I've got my work account, my personal account and my school accout logged in. Within those account only my school account has M365 licenses so I used it to activate and log into all of the M365 apps. But since I've got OneDrive logged in for the multiple accounts on my desktop, the other account was logged onto M365 as well. No big deal since I primary use my school account.

But a few months ago, I am starting to notice that every time I turn on my computer and open Office/Outlook, the account on the top-right corner will changed to my personal account, which does not have M365 license. When I press it, it only lists out all of my other microsoft account except for my school account. It says that I need to "fix my account". When I press the "log in" button, a dialog box shows up for my to enter my account. I entered my school account email and then things will went back to normal without the need of entering my password. But the next time I boot up my computer, it will happen again.

I tried uninstalling Office but I think that is not enough since when I reinstall it, the accounts will come back without my need of re-entering all the credentials.

It only happens on this particular computer. Can anyone help? Thanks!