The earliest recollection of this bug is traced back to PAN-OS 8.1.15 - January 08, 2024.
This bug is fixed in PAN-OS versions 9.1.2, 8.1.15.
Fixed an issue where an incorrect optimization could cause IP address-to-user mapping to not update within 60 seconds.
For more information:
https://docs.paloaltonetworks.com/pan-os/8-1/pan-os-release-notes/pan-os-8-1-addressed-issues/pan-os-8-1-15-addressed-issues
https://docs.paloaltonetworks.com/pan-os/9-1/pan-os-release-notes/pan-os-9-1-addressed-issues/pan-os-9-1-2-addressed-issues