Old demoted DC servers still have DC role/monitors on them

Hi Everyone,

we have quite a few old Domain controller that have been demoted and no longer are running those services but SCOM is still monitoring them as DCs. 

Is SCOM doing a period discovery of the roles for each server? Is there a way to force this somehow so that role can be removed from those servers?

All demoted servers are still visible under ( Monitoring>Microsoft Windows Active Directory> DC State ) view and all AD DC monitors are still visible and enabled under health explorer for each. 

Thank you