OP, are you stalling now? If not it may be a sign that you are about to...
Do you do shoulder presses/military presses? If not now is the time to start doing them. One of the most underrated lifts in the gym. In terms of your shoulder being weaker than your chest, technically that isnt unusual and expected. I think its the weakest muscle when your lifting. This is why your number for a shoulder press/military press is always the lowest lift compared to your squat,deadlift,bench, and row.
Having an unbalanced body part is one of the main causes for pain when lifting. You cannot be benching say...315 and have shoulders like a schoolboy. You gotta balance it. Cause your shoulders may be getting strained and thats why your feeling that pain.
As for lowering the weight, sometimes that is an option also. Sometimes what i do is go back down 15 pounds whatever the lift is and then just start the journey over...
This is true. After 20 years of lifting I finally got popped with a bone spur in my right shoulder. Basically if I go real heavy on the bench press, incline press, flyes, that same bone spur will tear the deltoids in my right shoulder and I'll feel a burning sensation there.
shyt is depressing right now and I could've avoided it by giving my shoulders more time but as a dumbass I concentrated on blowing up my chest because that's my main glamour muscle. My chest seriously overpowers my deltoids and it got to a point where they said no more.
My orthopedist thinks it's small enough where I can soend time with a physical therapist for the next year to strengthen my shoulder. If that doesn't work then I'll have to get surgery to shave that shyt down and be like "new".
At my worst I would have a constant pain in my right shoulder, a popping sound in my shoulder whenever I lifted my arm above my head, and worse of all I can't sleep on the right side of my body.
So yeah, if you're feeling a pain in your shoulder after benching on a regular basis, get checked out/x-rayed.