Is this using stock plastic slide?
Slide going back too far, jams up. When slide is jammed back, you pulled trigger, and the slide lifts and moves a tiny bit forwards.
And feels like you have to smack the back of the slide to get it sliding forward.
If you take the slide off you might notice lots of wear on the top of the Trigger Lever. (G26-36)
I think this is the area of concern. If it is bent in the wrong direction (up/down) your going to have problems. And the trouble is. I wouldn't go randomly bending things or your going to have more problems.
And I cannot suggest which way to bend what,
It will either jam the slide on its way back, or cause the lever to slip off the hammer mech and not fire the gun properly.
I know guarder has released a replacement trigger lever to correct the "slipped" problem. But I cannot say you want to buy additional parts at this point. This problem appears common with the G26/G17 series.
Link To Guarder Part