Question About Bench Press Sticking Point

Hi coach, I have been following your 4 day “approach” with one day dedicated to Bench, SQ, DL and Military Press, based on my personal weaknesses I have chosen the following assistance exercises for each move

Bench: Close grip bench and 1/2 top-half bench from pins

SQ: Front Sq and Pause squat (2-3 seconds)

DL: weighted chins and sumo DL

MP: Incline Bench and BTNP

All main lifts are progressing so good except bench press, I ALWAYS get slow and lose strength mid way when my elbows are 90º, I dont know if it’s a shoulder issue because maybe I dont do much assistance exercises for front delts…

What would you recommend? maybe doing more delts on bench press day after the assistance exercises? Change something especial? Thanks