PMKID Generates Wrong ESSID And Password From Hash
I think, I got a solution for your "problem". By latest hcxtools commit
I added a new option to hcxpcaptool to filter output by a single MAC address:
--filtermac=<mac> : filter output by MAC address

If you select this option, all packets which doesn't contain this MAC in address 1, address 2 or address 3 are ignored. So if you run

hcxpcaptool --filtermac=your_target_mac -o target.hccapx -k target.16800 *.pcapng

target.hccapx and target.16800 contain only hashes that matches to your filter MAC address

Keep in mind: this will affect complete hcxpcaptool output!