I was so troubled, too when I added a work Microsoft account to my computer. It made me including all other users of the computer to change their 4 digit PIN to 6 digit PIN. Then the passwords had to be changed before accessing their personal user accounts. I therefore decided to remove the work account from this computer to a different personal laptop. There was no remove/ delete account button in the settings. I followed this discussion but then realized that my computer had different removal buttons. I believe this shall help somebody.
I clicked on the ACCESS WORK & SCHOOL, MICROSOFT ACCOUNT (to be removed), and DISCONNECT. After a few minutes the work Microsoft account appeared again. I clicked DISCONNECT for 2nd time and the account vanished.
THEN
THEN CLICKED A 2ND TIME TO DISCONNECT.
The account vanished.
I restarted the computer.