Outlook 2016 Desktop Client asking for Password continuesly

Good afternoon community,

my Outlook 2016 Desktop Client (Version 1808 Build 10730.20280 Click-to-run) is keeping asking for my account password. Even when I type it in and try to save it, it won't work. When I hit the cancel button I can access the account but in the status bar it says "Password needed". That is happening when I am outside my companies domain working from home. When I connect to the companies network there is no such asking for a password. We are working with Exchange 2016 on premise. Any idea what could cause this or what solution I could try. I am not the only one in my company that has this issue.

Any advise would be much appreciated. :)

Regards

Daniel