We m9a1 gen2 slide not returning

[Kresomatic]

Couple days ago I bought a we m9a1 gen2 and it worked fine for three days and now this happens 

https://youtu.be/5XH-9ikQEzA

Slide won't go all the way back

Any ideas?

 

[johnnyj]

Strip the upper down look for and broken bb's etc stuck in the feed ramp or around the hop only needs to small . 

 

[Chris_B]

I had the same issue on my WE M9, the fire selector arm was broken.

Take your slide off, turn it upside down, and move your fire selector into its various positions (back and forth) and look for the small plunger move in and out in the grove of the slide.