iPhone exchange email password fail

My iPhone keeps requesting the password for my exchange email account. I have input the correct password and reloaded the email account but nothing works. I can see and reply to my emails but the pop up window keeps rejecting my password. This is a problem that appeared suddenly on 12/25/22. I have an iPhone 12 w/iOS 16.2. My iPad works fine with the same exchange email account. So I don’t think this a Microsoft issue.

Please help!