You may have a galled ballbearing inside, or you may not have fully cleaned out the contaminate. If it was something sticky it may be hard to get out. If you run your bearings with no lubricated break in, the change of galling a ball is much greater. Same can be said for no lube at all. So check for flat spots on all the balls, but chances are it just needs too be cleaned better, as there doesn’t’ tend to be enough friction to induce galling in yoyos since the string will just slide on the bearing. Nail polish remover isn’t very good. Most of them have perfumes, and coloring in them that can/will be left in the bearing. You may also have a bent cage, (the thing that holds the balls), or if you replaced the shields one may be installed in a way that has it rubbing or it may have been damaged in removal.