Outlook repeatedly asking for / not accepting password

I imagine we all have seen Outlook not accepting a known email password. When we do, we delete all the credentials in credential manager and the problem goes away. Now we have one client who gets this regularly – one user sees it at least once a week while other users go 2 weeks to 1 month before it happens again. Their email is Office365 hosted on GoDaddy and their Office365 Application Suite is licensed through another vendor. So, we were thinking maybe there is a problem with GoDaddy or there is some sort of conflict with hosting email on one service while software licenses on another. GoDaddy support says the problem is Outlook and pointed us to an Outlook repair tool, but the rest of our clients (non-GoDaddy email) don’t have this issue. Thoughts?