Took several pieces of y'all's advice.
I swapped 1 of my 2 leg days with a third chest day. Added cable fly and dumbell bench (added some shoulder lifts as well but not relevant here) dropped the weight considerably (55-65lb for db press), and focused on very slow presses, trying to squeeze as hard as humanly possible on each press.
I can definitely kind of feel when I use the chest to press with the dumbells instead of my arms. Never knew it was so hard to detect and correct leveraging your arms instead of pecs with barbell!
I think for barbell bench, going to use half my reps for very slow pressing with focus on isolating/squeezing my pecs and the other half on strength.
@KvanH i didn’t see your recommendation in time but will incorporate that next time as well.