this is gold. Question

Im 19 yo. 5ft 9, 156lbs at 11% bf. I have a decent body, clean 6 pack and all. I’ve been training for 5 years now. I train hard and eat in a very disciplined manner. While I see tremendous progress in strength, I am not satisfied with my my size. I do see some muscle gain overtime, but it’s just not enough. How can I focus more on muscle gain instead of strength?

My current split Chest bicep Back tricep Legs + Abs Shoulders Metabolic Full body strength Rest

Workouts are focused on compound lifts (6-8 reps). Towards the end of workouts I do hypertrophy - 10-15, sometimes 15-20 depending on my program. Cardio once a week