first, with the carrier removed, hand rotate the hammer to see if the discon will catch the hammer.

i don't know what brand parts you are using for the hammer, discon and trigger, but if the hammer is not engaging the catch surface on the hammer you may want to try another brand.

then, if the hammer is being caught by the discon, make sure the carrier is driving the hammer back far enough for the discon to catch the hammer. test this by running the carrier rearward with the cover removed and observed the movement of the parts as they move.

press down on the carrier and try the test again if it doesn't catch the hammer with just a straight back motion of the carrier.

check your disconnector spring and forward travel of the discon and the trigger. the trigger may be blocked from full rotation (when pulled), affecting the discon's rotation. check that the trigger does not interefere with the floor of the receiver.

try another hammer. try the commie hammer that came with your kit. if it works, get a restararms set.