MS Teams / Mindmanager 2019 problem with sharepoint file

So I try to open the mmap out of Teams via File open in Desktop App. The Desktop App starts but the authentication for the sharepoint doesn't allow my credentials. I'm shure that they are right, but it seems, that the location is wrong and Mindmanager 2019 tries to log me in to the sharepont maine page, where I have no access to.

If I open the mmap document from the sharepoint directly the file opens whitout any problem, but that overrides the document if i save it there.

Does a upgrade to Mindmanger 2021 helps or is that a structural problem?