Issue OneDrive MAC client SharePoint unable to access

Since a few days my co-worker has this really strange issue. 

She is owner of a couple of Microsoft Teams. And synced them to her Mac and Ipad

But once she opens the Library's or tries to open them in MSWord. See gets a credential cache issue which keeps popping up.

Online she can work on the documents but offline the issue exists. 

When i try to open an document of within word i can not open the SharePoint sites i see them but can not drill into the librarys.

I already opened a ticket for this within Microsoft(#17987357) but the support engineer is trying to do Windows commands on mac. And also reinstalled the mac to be sure it is not a system issue. Even did sent Logs to him.

It would really be nice if we can solve this issue. As the user is getting frustrated about Microsoft Products.

Please help!