I'm having the same issue with wax and shatter sitting at the top of the coil. I am firing at 7.34v, herc is at 2.3 ohm, and I got a red rod before loading the concentrates. And my rod is in the correct spot in the tongs. But I don't understand "remove the middle black PTFE shield, and re-position the rod, gently screw it in and when you feel resistance stop, put the stainless top cap and the mouth piece on top, try it now and see if this fixes your issue."
I don't have a black ptfe shield. Are you referring to the ptfe shield at the bottom of the centerpost? And leave it off, putting everything back together, and firing it up?
And when you say "reposition the rod", do you mean in the tongs? sorry all just went over my head.
if herc is 2.3 ohms then its good. the black ptfe shield is the outer black center tube that connects to the bottom adapter and to the mouth piece.
do you have the 71 or the 74x?