failed authorization on bitbucket server remote projects

failed to refresh remote projects on Bitbucket Server. Authorization-Check works fine. No problems with same User and SourceTree on MacOS. 

Error Message after filling list with some projects:
'Die Mitgliedschaften für den Benutzer können nicht vom Remote-Host gelesen werden
Failed to list repositories for team [...] : You do not have permission to access URL 'https://bitbucket.[...].com/rest/api/1.0/projects/[...]/repos?limit=1000&start=0' please check the user credentials associated with this account. The request returned with status code 'Unauthorized'.
Sie haben keine Zugriffsberechtigungen für diese Ressource.'

Mentioned failure-project change on every request.