Think the “issue” has been solved....bottom line...my fault for not noticing an “equipment failure” setting primers too deep....which combined with generous headspace on FL sized cases...resulted in light firing pin strikes.
Picture of the culprit below. For years I have used this primer pocket uniformer (without issue) to remove powder residue in primer pockets. For some reason, the set screw must have loosened enough to let the mandrel/cutter pull out a few thou which resulted in primer pockets getting a tad too deep on a batch of brass that I had just annealed after 12 reloads.
I reset the cutter depth by bottoming it out on new brass and added a bit of loctite to the set screw. Should be good for another 20,000 rounds. Oh well, now I have a good supply of primers. Live and learn