If you purge an account and recreate it, you can assign the same UPN but the new account won’t have the same object identifier as the original. That will be your problem because the workloads use object identifiers (GUIDs, so always unique) to link data together. But I would push back on Microsoft support and ask for further help. If there’s a problem with an account, they should be able to figure out why. I assume that you didn’t do anything to cause the problem, which would then allow Microsoft off the hook…

If you want to delete and recreate, backup everything first. You could do a content search to find everything in the account (assuming Office 365 E3 or above) and export it to a PST (mailbox) and individual files (OneDrive). Then use that data to recreate information for the new account.

But all of this is expressed with the strong caveat that I do not know the precise details of your circumstances, which is why you should work with Microsoft support as they can sign into your tenant to see what’s happening there.

BTW, here’s another approach: https://office365itpros.com/2022/03/23/delete-azure-ad-user-accounts/

All true. The Graph API for users returns 100 objects by default. If you want more, you’ve got to ask for them.

Thank you so much!

Both are functionally the same and remove a user account object permanently from Azure AD. The Remove-MsOlUser cmdlet is just older. The other is based on the Azure AD Graph (which will be replaced by the Microsoft Graph in due course).

Yep. Hopefully, Microsoft will make this a non-preview feature very soon.