I have several workspace apps in a large environment that have been in production for some time. Recently, as part of an overall cloud migration initiative, the UPNs (userPrincipalName) attribute of users in Active Directory was updated. It went from "doejo@corp.contoso.com" to "john.doe@contoso.com". Users were previously in Azure AD / Office 365 using the old name and were synced using the new name. When attempting to update the content pack the error referenced in the subject is thrown in a red box showing users with the old name even though they are updated to the new name. We can remove the user from the list and readd them with the new name and update the pack but upon going back in and adding a new user, the same error comes back.
Any suggestions?