Resolve Microsoft Entra ID OIDC user account sync conflicts in Apple Business Essentials
If you disconnect from Microsoft Entra ID and reconnect, you can choose whether to merge the Microsoft Entra ID user accounts. After you reconnect, check the provisioning logs. After all the accounts are synced to Apple Business Essentials, you can choose to disable Auto Merge to avoid any account merge issues.
Manually resolve Microsoft Entra ID user account sync conflicts
If you have a conflicting user account with Microsoft Entra ID, you can manually resolve the conflict.
In Apple Business Essentials, sign in with a user that has the role of Administrator or People Manager.
Select your name at the bottom of the sidebar, select Preferences
, then select Managed Apple Accounts 
.Under the Microsoft Entra ID section, carefully read the Account Conflict message, then select Resolve.
Select the Download Conflicts button to download a list of account conflicts, then review the conflicts.
If the conflicting accounts are identical to each other in Microsoft Entra ID and Apple Business Essentials, select Merge.