Cats are very fussy about their potties. I have 6 litters for 5 cats and they use them all. But some cats are very picky and sounds like Ozzie is one of them. Ozzie is not happy with the change you have made with his potty and is telling you so in no uncertain terms. Can you have both boxes together. Ozzie will most likely go right back to using his normal box. Put the other box back where it has always been and put the other one in another location. I bet Ozzie will not leave you another present once you replace the new potty with the one he is used to.

Keep us updated and good luck.

BTW...rule of thumb is 1 more litter box than cats. Works well for me.

Michelle