Okay, if you pull the hammer down while it's stuck like that does the slide move freely?
Do you have to manually (perhaps quite forcefully) push/tap the slide back into battery (i.e., fully forward)?
If it's the latter, remove the slide and check your blowback unit (BBU) by pulling the loading nozzle all the way forward: check the o-ring on the piston head (if one/was is present) and make sure if hasn't come off. I've seen some get caught/shredded by the loading nozzle and end up torn and jammed at the base of the BBU.
Also pull back and release the nozzle and make sure it's moving freely and smoothly.
If necessary, remove the the BBU (flat head screw holding the rear sight and hex screw at the rear of the slide: don't lose the small long-ish spring when you remove the BBU) and lube the piston head. Check the inside of the blowback unit and ensure it's free of dirt/debris and slightly lubed.
Make sure the hex screw holding the BBU isn't excessively overtightened as it may pull the BBU back at a weird angle (fraction of a degree) which can interfere with the loading nozzle. Tight is okay, I'm talking about not torquing down on it like a gorilla.
__________________
|