I had some snugness with the Tobeco clone I bought. There's a screw (part #9) which was a little tight, plus on the air hole/finger ring (part #5) there was very slight burr on the edge mating to the ring with the Svoe Mesto logo (part #26). I gently rotated that on a piece of 800 grit wet/dry sandpaper and that smoothed it all out. Then when reassembling those parts I did not tighten the screw (part #9) too tight, just finger tight with the screwdriver and it now turns very smooth.
#9 needs to be proper tight.
Keep an eye on your ohm readings - if they start jumping about it's cos #9 has worked loose.