Is this a single-action trigger by any chance? I installed it and reassembled the gun and there's no DA.
Edit: I am a miserable tinker of guns... Have DA/SA, just need to tweak. A lot.
Your picture looks like a DA/SA trigger. If the trigger has reach & over travel adjustment screws, if the reach reduction screw is in to far it will not reset in DA and if the over travel screw is in to far the sear edge will catch on the hammer and damage the sear. Does your gun have a disconnector attached to the front end of the hammer. Post more pictures