Windows Update Reports - forbidden

Question

I am trying to change the Loganalytics Workpace for our Windows Update Reports.

I created the new Workspace from scraptch 100% after documentation. Unfortunately it doesn't work to remove the old Workpace from the Portal. It doesn't matter if I try it in M365 Portal or Azure Monitor, same error:
400 Bad Request
Resource key 3034cdac-24bf-4584-96ee-970427389c1b_LogAnalytics is invalid. Identifier must be a GUID.

The code executed is

https://graph.microsoft.com/beta/admin/windows/updates/resourceConnections/3034cdac-24bf-4584-96ee-970427389c1b_LogAnalytics

In general I would say I have nearly the same error as described here: https://www.loebmann.tech/windows-update-for-business-reports-error-403/

Unfortunately the solution doesn't work.
Get-MgWindowsUpdatesResourceConnection | select * | fl

Get-MgWindowsUpdatesResourceConnection_List: The server responded with a Request Error, Status: Forbidden

Used a Global Admin and set the correct rights in the PowerShell Graph Connector (connection works).

Would appreciate any help!