Random fragments being logged with no associated rule

[anallama]

Hello, just to start off with, I don't believe this is truly a problem, more just curiosity. This has only been happening for about a month now as shown in the attached image, with random single fragments being blocked and logged, despite the fact that I have each of the offending source IP ranges blocked by pfBlockerNG on a list with logging disabled. The destination IP is just my public IP in every case.

I saw one other thread posting about something similar over IPv6, but I am only using IPv4, and that thread had no conclusion. Can't really do a packet capture, practically speaking, as I have no idea when these are coming, and obviously it's very infrequent. Just curious if anyone has a clue what or why these might be...