Without knowing anymore, I am guessing you are moping, spritzing, saucing, etc.
Put your chip tray in the unit about an hour or so after you add the meat, about when you probe it. You may be starting too early with the smoke.
If you are moping, spritzing or saucing you let all the smoke out every time you open the door.
You can use an aux. smoke generator. If its soft and low like AMPs a full tray will be needed. It works great. If you are using something like the
masterbuilt cold smoker it smokes well but for a shiorter time. One slow and long, one fast and short.
I never had problems just reloading the tray, usually the inital charge, and one maybe two reloads. Don't expect to see clouds of smoke exiting the vent. If its smoking like that you are not getting any good smoke taste. If you can barely see the smoke, almost clear, actually a thin blue smoke, to are doing all the good.
Do not hurry your reloads of the chip tray. you want to allow the chips to reach a white completely combusted ash stage. Blacken chips mean you wasted the best part.
Just some ideas that came pretty quick. Leave the door shut, if you are lookin you ain't cookin. Learn to use the vent to regulate the smoke which regulates how fast it peters out. White ash is easily achieved with a wide open vent, but a semi open vent allows it to smoke longer due to slowing the ability of oxygen to reach the coals to cause either a smolder or combustion.