It's cylinders 3and 6

Question

Everything else has been checked

Answer 1

Cylinder 3 and 6 are the companion cylinders,  3 and 6 are of the same coil pack, this is where you rule out a mechanical condition . Experience make you suspect that the coil pack is faulty, but you already changed the coil pack this is where the ICM where the coil pack sits on. is more suspectable since you already check everything else.