Our environment is hybrid, so I cannot make any changes from the Microsoft 365, Azure or Exchange admin center using powershell or UI so anything that starts with connect-msolservice will not work.
Due to recent security changes we have changed user logins to email@example.com but their email addresses remain firstname.lastname@example.org.
Recently we have had a couple of new employees created, when the remote mailbox is enabled (from the local exchange management shell) it should generate the smtp:email@example.com alias instead it is generating firstname.lastname@example.org in the Microsoft 365 Admin centers. This is causing some issues with internal email routing from systems as it is looking for the email@example.com address.
Local user account reads: UPN: firstname.lastname@example.org
Attribute Editor: Every value reads email@example.com or tenant.onmicrosoft.com except for the userPrincipalName (last edited value) reads like above.
I have tried manually updating the users "inbox" in the exchange server to add the firstname.lastname@example.org the Sync Service manager is working and attributes are selected in the properties of the connectors but it never reflects the change on the Microsoft 365 Admin Center(s)
Does anyone have any ideas how I can force this change up to my Microsoft cloud environment I would be greatly appreciative. I believe I have tried searching everything my little Google-Fu brain can find but I am at a stand still