WhiteSilverado15

Ok so I drive a 15 Silverado with the 5.3 and 6 speed. Truck has 54k on it and I’m having an issue where I stumbled between shifts and almost feels like the rear end slips the catches. I have replaced maf, map sensor, throttle body, tranny fluid, rear diff fluid, torque converter and am still getting same issue. Any insight would be great. I figured I would do fluids as the truck is 6 years old anyway. Thx