[Hectic]

Tappet plate is good too?
The trigger issue could be the spring is on the wrong way.
The feeding issue can be the tappet plate its spring or the nozzle or the cylender head itself. Lotta times parts in clone gearboxes doesnt work out tok well and vise versa like what happened to me. I got a lonex shelltryed putting my echo 1 parts in it. The cutoff lever doesnt work properly in the lonex shell so i got no semi and the gears from the echo1 didnt work in the lonex shell (for long) got 40 of 50 rounds out of it and they stripped. Apparently echo1 and jg gearboxes are off in the location of the busbings and as such their gears are a lil off to compensate for this putting em in a wuality box made the sector and spur gear run too close together and chewed them up fast. Put in lonex gears works great.
So it could just be fitment issues of the new parts.
As for another potential feeding issue. What bbs are you using. If you load ghe mag then flick the lil switch that activates the bb retainer do the bbs all fly out or does the mag jam up?