Office 365 Calendar: can´t connect/sync anymore

I had a working connection between Garmin and Office 365 - until 12 days ago.

Since then apparently the link between Garmin and O365 is broken.


Does not show up in the Account Information (Applications: You’ve given the following applications permission to interact with your Garmin Connect account.)

Clicking on the 3 dots and then "connect to Office 365 calendar" then prompts for O365 credentials - then nothing, switches back to calendar, but no sync established.


In the Android Garmin Connect  App

Settings | Partner-Apps | Microsoft Office 365 = can enter credentials =error message


So, not working.

Please advise