I painted my custom game with the 2X on the suggestions of others and had some issues on the front similar to yours.
In my case I used high-fill autobody primer and the 2X heirloom white as the base and 2X red. No issues on the side, just the front. After I stripped it down and re-primed it was fine. So, as others have said, probably something in the base wood.
Going forward I'll prime with Kilz.