The earliest recollection of this bug is traced back to PAN-OS 8.1.17 - January 09, 2024.
This bug is fixed in PAN-OS versions 8.1.17.
Fixed an issue where Data Filtering profiles did not generate a packet capture (pcap) for Server Message Block (SMB) when action was set to Alert.
For more information:
https://docs.paloaltonetworks.com/pan-os/8-1/pan-os-release-notes/pan-os-8-1-addressed-issues/pan-os-8-1-17-addressed-issues