How to get rid of RestrictedGroups/ConfigureGroupMembership settings?

Colleagues had created a configuration profile with a RestrictedGroups/ConfigureGroupMembership policy to overwrite the local Administrators group on workstations. We have removed the policy assignment weeks ago, but on some devices it is still applying:

We have some exception devices where we want to have the Administrators group managed locally, but on every Intune policy sync the group gets overwritten, and any changes done locally or by GPO are reverted.

On an affected computer, I can see the old policy in WMI class MDM_Policy_Result01_RestrictedGroups02, but I cannot delete it from there. I do not see the old policy in WMI class MDM_Policy_Config01_RestrictedGroups02.

How can I get rid of this policy?