Dropping 10% of your shots sounds more like a concentration issue than a physical one.
I agree. But why only with 9mm. Never with .40 or .45. You could say I'm getting bored but I could shoot an M&P .22 or .380 EZ all day without it happening.
I believe I inherently don't like the sharpness of the 9mm impulse and it requires greater concentration to avoid anticipating the shot. What I'm trying to find is an exercise to fix it.
I'm uncomfortable with the instructor's recommendation of "just shoot more 9mm". I'm afraid it will be contagious and spread to other calibers.