Able to remove access inherited from Management Group with subscription admin rights.
With subscription admin access, people are able to cleanup access inherited from Management Groups, which shouldn't ideally be allowed.
This ability is not authorized. A subscription owner is not able to remove any inherited accesses. Any changes to the role assignment must be made at the assignments location on the management group.
If you are still seeing this, please submit a Support Ticket via the portal to have this addressed. Thanks