Samsung J3: MS Outlook randomly ask for password

[AC Question]

I open MS Outlook and get pop-up "you must re-enter your password for your account nnn@nnn.com"..

so I hit OK and get

"this email address is already added"

I can find no means of re-entering my password other than deleting the account and reinstalling it.

Is this a known issue, please? Is there a fix?

 

[the tall guy]

Hi, so when you delete the account and re-enter it, does the problem continue? Is this an app you have installed on your phone?

If you need additional help or have more questions or details to share, please join the site so you can reply in this thread. See this link for instructions on how to join Android Central.

 

[AnnDroyed]

Thanks tall guy. Sorry it's taken a while.

Deleting the account and re-installing resolves the issue, but after a week or three it suddenly recurs for no apparent reason.
It's the standard MS Outlook app that I installed off PlayStore. (I find the default mail app unsatisfactory)