You mentioned your plugs being rated for 33 dB reduction. I was at Walmart yesterday grabbing deer tags for the kids and noticed a pair of plugs rated the same; problem was, the standard reduction was something like 12 dB with “normal” conversation. They are supposed to attenuate concussive noise and I’ve tried similar plugs from SureFire to no avail. Actually rung my bell shooting .45 ACP with the first shot and on went the muffs. With those on the plugs did very little.
It may be a dead horse, but consider swapping what you have for other brands if you haven’t already, everyone’s ears are different. Beyond taking more shots at game without ear pro than I care to admit to I know from almost daily use that my left canal is larger than the right and has always been more acute, proven yearly by the audiologist.