This... and also what ammo is giving you trouble? I've had issues with some RNFP before; I try to stick to RN only (target). Haven't had issues with any SD ammo.
Is this happening when you are first attempting to chamber a round, or while you are shooting it?
If when first loading it make sure you are pulling the slide completely to the rear, release it and let it go forward on its own, don't ride the slide forward.
Clean & lube...
Mags...clean & lube..
Dont ride the slide.....slingshot.
Additional....
Is the gun new?
Pull the barrel out and drop rounds in...plunk test...do they fit?
Feed ramp look and feel ok?
Seat the rounds in the mag.
One mag or all?
Followers function ok?
Clean, Lube and get a few hundred rounds through it and life will be better.