Users added to users.allow file are unable to log in
Users added to the users.allow file are unable to log in. The account is Unix enabled and the username is correct. Also, groups added to the users.allow file are working correctly.
The userPrincipleName AD attribute for the account had a domain that was different from the name of the domain the account belongs to. This mismatch between the UPN and the domain name caused QAS to be unable to recognize the account as allowed.
Correcting the UPN attribute of the account allows the user account to be able to log in again.