So I made a doctors overcoat ST and Plague Mask ST with 3 slots, and cursed spire spell with 2 slots
Doctors overcoat ST was made using a 3 slot hollyhock hide and had 3 slots
Plague Maskt ST was made using a magicians tophat with 3 slots
I then went to the pet yard, saw the cursed spire spell lost it slots so I fed it to my pet and then I went back to the vault only to see that my doctors overcoat and plague mask suddenly had no slots