Bad smell left on clothes all of a sudden?

Howdy all! So, I'm not sure what's going on nor how to fix it currently.

I've been using a Samsung HE front loader that I got new back in '21 or some such and for the most part it's been pretty great.

Lately I've been noticing my shirts have been coming out smelling... bad. One of the best ways to describe it is that it reminds me of the smell of used P.E. clothes back in high school that you left in your locker; that gross 'tangy' smell.

-I don't use fabric softener, I use distilled white vinegar 5% (and have been for quite a while, maybe 3+ years?).

-Currently using the 2nd giant container of the same detergent I was using prior (might be 'ARM & HAMMER Plus OxiClean Odor Blasters').

-I used a washing machine cleaning tablet (Affresh or similar).

-I did a cycle with just bleach. Then another cycle of just water right after.

-I wiped off the filter & drained a good bit of 'old' water from the filter area (bottom left of machine).

-I wiped the door seal area with a washing machine wipe.

I'm at a loss. What else could it possibly be? And it's weird also, the smell on some t-shirts for example is not even the armpit area but rather just some random open area like the side or back that doesn't see anywhere near the same amount of sweat.

Thank you for any ideas!