The Ready State Virtual Mobility Coach is like having a virtual Kelly Starrett in your pocket.
Stability exercises will help.
Do you sleep on that side?
Is the front of your shoulder, pec or collar bone area tight?
This can pull the shoulder forward in the socket and you hit bone on bone earlier within the range of motion.
Have you addressed internal rotation and extension of the shoulder?
Episode 315: Great New Shoulder Fix-Internal Rotation Tack and Stretch
Episode 89: Bro, Your Internal Rotation is Lacking
Episode 229: Shoulder Internal Rotation, I Has It
Look forward to your update on your situation