The explanation as to exactly what you do is a little vague.
But here are some things that might cause a similar problem.
1. All Semi Auto Pistols should be properly lubed.
2. Some are more temperamental when it comes to your ammunition selection. As I will explain my experience with my Kahr P-380. When loading it with Federal Hydra-Shok ammunition I must lock the slide to the rear with the pistol's slide lock. And then using my thumb push the slide lock down allowing the Slide to go forward with the full force of the slide and spring. It will chamber the round everytime. If I pull the slide back by hand and then let it go the round will not go all the way forward and the round is not totally in the chamber and locked into battery! If I push on the rear of the slide it will lock up! Although after the first round is in the chamber it will fire every round in the magazine without a problem until empty! I went to the New Hornady Critical Defense 380 ammunition with the Red Tip and I can pull it back by hand and release it and it will chamber every time. So your ammunition selection could very well be your problem. The Bullet configuration makes a lot of difference as to if it will feed or not. You should never ride the slide forward when loading any semi auto pistol or other semi auto weapon.
3. When firing the pistol Limp Wristing can cause the semi auto to not lock up after the shot or jam during the shooting process causing stove pipes and failures to feed or extract. In the smaller semi auto pistols which have less recoil force to the rear it is very critical that you grip them firm and do not allow your wrist and hand to move to the rear when they are fired. When the slide moves to the rear it must have enough forward resistance against the frame to allow the slide to travel completely to the rear.
Just a few ideas. If you could give us more details that would be great as to what you are exactly doing and what is happening. Or try the ammunition recommendation and be sure to lube the pistol.