Help: CR123 batteries=crap? Brightness issues w/Energizer PMHT1L

So, these flashlights are AWESOME for the first few days of use. Rated 300 lum and feel like more. Rated optimal 50 ft.

My problem is that after a handful of uses and cycles through the modes they go VERY dim. Like dimmer than the dim mode and that mode gets worse.

They take CR123 batteries as labeled on the case (although I can't actually find any labeled with the "CR", even Energizer brand only has ”123”, not sure if I'm buying the wrong ones?), and I've tried changing those out with no success, even though the battery tester says both sets are full. Sometimes dim from the start.
I've tried fighting the aircraft aluminum to tighten it more and increase pressure for contacts without result. I can barely feel the action of the button against the pin in the cap, even when depressed all the way.

I have 3 of these now because I figured maybe I got a lemon. The same thing has happened to all of them. Sometimes out of nowhere they will perform correctly, sometimes for a handful of cycles and sometimes for like a month or so on end.

As far as how frequently I'm using them, every few days because my truck's interior lights have an electrical problem. Also when taking my dog out. So not a lot of consistent time on, I'm not using them like a lamp or anything. Maybe a literal minute or 2 at a time. They've never been wet, and are rated IPX4 anyway.

Amazon reviews have folks saying they stop working after 3 mos or less, that the expensive batteries aren't worth it or sometimes DOA, etc. 4,233 ratings.

I'm wondering if anyone here to comment knows any hacks to help electronics like this, adding metal bits or even stuff like using a bunch of button cell batteries or similar performance from other batteries validated by electrician knowledge. I've come across this kind of "interchangeable" stuff before and thought maybe it is worth a shot here to since the issue bc these are fantastic when performing correctly.

Thx