Single/double doesnt really matter as to function, unless the port that the trigger goes through is set up for one hook and you have two. To make it work, you would either have to mill another slot in the port that the trigger goes through to clear the second hook, or grind off the second hook so that it didnt bottom out.
You have a problem with the reset spring on your trigger, it is not right, the trigger should go foward after it is released.
This could be from a few things. It could be that the short spring that goes into the recess in the disconnector is not long enough, or that the double wound hammer spring is interfering with the trigger because it is hung up on something and causing it to jam.
Both are simple fixes. This is not normal and until it is fixed, breaking it in, will not make it any better.