TM M9 trigger needs to be let go to work

[xaphor]

I bought this TM ages ago, extremely cheap. 

 

When I'm shooting the pistol I have to let go of the trigger for it get into a place where it can shoot again.

 

I can't apply any pressure to it if not then I cannot shoot until I let go of it..

 

Video below 

[Guest]

Video doesn’t work for me

Works now
 

Is it non-blow back? What does it do with gas and bb’s in the mag?

Video doesn’t work for me

[BigStew]

Possibly the spring on the trigger bar is gone. it's under the right hand grip panel.