Looks like damage from the packaging machine, used for the pliofilm PL sets.
That was my thoughts as well. So, assuming these sets are put together and sealed at the Mint, this damage happened at the Mint post strike. So not a die/strike error, but not really PMD
either, as the coin technically hadn't left the Mint. Does that make it a PSD
(post strike damage) MD (Mint damage) or just a beat on coin?