My IMAP mail suddenly stopped working

My IMAP mail suddenly stopped working

On my iPhone and iPad, IMAP stopped working for my Zoho account with the error "User name or password incorrect" and "Invalid credentials failure" however I was able to access via web with the same credentials.

Also stopped working on Apple Mail client. I double-checked all the settings on the desktop and on the phone, and all seems to be in order, yet I still keep getting that error. What gives?