I had this problem pretty bad last year, im still trying to figure out exactly what causes it, as some paint colors seem to get it a LOT worse than others, white is the worst of all. Ive changed paint brands, which seems to have helped, time will tell. Ive also switched back and forth between testors and armory, then back to testors again.
It could be your paint, or the humidity of the area, or the thickness of the coats... only two of those you can fiddle with, sadly. Try switching up your paints you use to rule that out... and multiple thin coats is the way to go with sealing (accidently thick coats will also leave terrible crackles which are annoying to fix.)
As to treating sticky ponies... it sounds funny, but put them in the fridge. For reals. For like 5-10 minutes. Til they feel dry. Then reseal them. Seems to help a bit. But not sure if it FIXES it or if its just a bandaid treatment. And results vary from case to case. Youll want to try to wipe off as much dust etc as you can before resealing tho, or the debris will be there forever.
Again, not sure if theyll stay dry that way or if it just puts the brakes on the stickies for a little while. I eventually discounted out the ones that had it bad in a fit of rage. =/
Best of luck. Let me know if any of it helps.