The screws and the coil must not touch the interior of the topper. I had a case where the deck ring wasn't right. If the issue persists, make a flat resistance without coil and ensure that the screws are flush with the posts, and check again. If you have again short, send us an email with photos to fix it.
The AFC ring's position is stabilised from the 510 adapter by design. The same happens when the Heron is screwed into the Paps tubes. You have to unscrew the Heron by half a turn, from the 510 adapter or the tube in order to turn the AFC ring. We designed in that way, because most people have a constant draw preference, while a loose AFC ring would be quite annoying.
This happens mostly due to more or less fluff than is required. Too thin and it can't hold the juice, too condensed and floods after a while, so spread it evenly to have a uniform density with a needle or the fork. Try with a strip of fluff with 2-2,5" length and 0,6" height. Your cotton edges have to be short and be sure the fluff is touching the inner walls of the tube without any gaps.