Outlook mail stopped working with native Mail on iPhone

My university controls the account and password. It is for all of my access and I can not change the Microsoft account password. Starting last week, after using it for years, I am getting the error message "Enter the password for the Exchange account "XXXXXXX". When I do, it just keeps asking me for the password and does nothing. Everyone in a while it will connect for one time but then not connect again for several hours. The University IT says it is an known apple issue with new accounts and they can't do anything to help even though mine is not a new account. Now my apple calendar won't sync with my outlook calendar either . No understanding why after years it just started happening. I did need to install the Teams app on my phone. It is the only thing that has changed.