User ID / UserPrincipalName domain O365 not equal to local domain, Domain Authentication

[plebras]

Hi,

We have a problem for a customer with authentication.

The local Netbios Domain is  localdomain (example) The local Dns Domain is localdomain.lan (DC=localdomain, DC=Lan)

90% of the users have an Office365 maibox . The link was made with the UPN and The UPN was modified.

Eg : I have a user LOCALDOMAIN\Test  = Test@localdomain.lan but Tthe UPN is eg Mister.Test@officialdomain.com (example)

User Agent (last version) are installed on Domain Controllers (Wmi seems to give other problems)

The user logs into the domain with LOCALDOMAIN\Test only.  But Sometimes the authentication gives test@localdomain.lan (Windows 10  and often when computer goes out from sleep, but we do not know why) on User Agent and Controller.

So test@localdomain.lan is not in any attributes of Active Directory for the users And Palo ALto does not get the correct user (no match) . The logs display test@localdomain.lan, but no match  to the rules. On the User Agent logs, we have test@localdomain.lan.

We can modify the link to Office365 (the customer does not like)  or add a new attribute (we have to maintain it)  but  is there another solution ? I tried to add sAMAccountname@localdomain.lan in the Alternate username but it does not work ( User Authentication/Group Mapping Settings)

Thank you