I got to figure out what was the issue and it was a change which recently been pushed by Microsoft. Mapping error “Application mappings are not valid” which is not allowing the users to sync.
Issue had recently popped up due to some back end new patch update at Microsoft end which is not allowing to map Primary key attribute “ID”. Now when we are trying to map the attribute it’s not working. Getting below error:
Checked MS documentation(https://learn.microsoft.com/en-us/azure/active-directory/app-provisioning/use-scim-to-provision-users-and-groups#step-2-understand-the-azure-ad-scim-implementation) it says ID is a required property now. Earlier I could map this TargetAttribute (ID) with SourceAttribute (OriginalUserPrincipalName)
After restoring the mapping and assigning with some other custom attribute the issue seems to be resolved.