The earliest recollection of this bug is traced back to PAN-OS 10.1.9 - July 22, 2025. This bug is fixed in PAN-OS versions 10.1.9. Fixed an issue where the alternate name was not getting copied to user-Fixed an issue where user-attributes for users in custom groups were incorrect, which caused username formats to not match the user. For more information: https://docs.paloaltonetworks.com/pan-os/10-1/pan-os-release-notes/pan-os-10-1-9-known-and-addressed-issues/pan-os-10-1-9-addressed-issues