>>
What rep ranges have you tried? Have you tried it with cables or just dumbbells? Have you tried with lighter weight for 15-20 reps with the volume spread out for 3-4x a week? Or pausing at the top for 1-2 seconds? You can even do light sets a few times a day (not close to failure) with a resistance band or something to increase the frequency even more. Other shoulder work like incline DB pressing, face pulls, etc will work them a little too. I’m also a fan of 15-20 rep upright dumbbell rows with good controlled form. Lu raises are good too.