What are you trying to do with the credentials? The role recently changed and the Device Administrator role is available for assignment only as an "additional local administrator" in Device Settings.
Not also that the privilege does not take effect immediately - only when either a user signed off or after four hours, when a Primary Refresh token is issued. If you have a Premium license you can follow the guide to manually assign the role. https://learn.microsoft.com/en-us/azure/active-directory/devices/assign-local-admin
If you'd like you can send me an email at AzCommunity@microsoft.com to get a support case opened for this and further troubleshoot.