Bersa TPR9C slide stuck

Howdy, I need some help fixing my new Bersa. It’s the first gun I’ve ever owned, and admittedly I don’t know much about firearms. The first few weeks I’ve owned it, it’s been wonderful. Fun to use, pretty easy to understand, yadda yadda.

However, last weekend the slide stopped moving almost entirely. I dry fire it a bit just to get used to the trigger and pull the slide back often to try and get more accustomed to it.

I took it to my local range and the guy there fixed it instantly, behind a door so I couldn’t see it. He just said he placed it on a surface and pulled back using “brute force”.

I shot 100 rounds on Sunday with it, it performed as beautiful as ever. Today after I got home from work, I went to practice cocking the slide back and the same thing happened again. I have no idea what’s causing it or how I can fix it outside of bringing it back to the range.

Please, if anyone has any input it would be greatly appreciated. Thanks.