My beautiful kitten Tyrone has a vet CLEAN BILL OF HEALTH but will not stop going outside the litter box

Need cat advice yall I’ve had my fair share of cats in my life and Tyrone has been my toughest one yet but the most lovey-dovey. But recently I just moved into a new apartment almost 2 months ago and he’s adjusted pretty well he gets along with the animals in the house and my roommates but for some reason like a few weeks into living here he is using the bathroom outside of the litter box it’s not all the time but he does. He never does it when I’m here though so I got him fixed thinking that would help but he is still doing it and I’m not just talking about him going number one he’s going number two as well. his litter box has a cover on it, a few things I’ve tried are a different litter and a new litter box, I’ve taken him to the vet and they said he was healthy, I got him fixed, he has two litter boxes and I’ve cleaned every spot extremely well. I’ve also put the poops back into the litter box right in front of him. I need my cat experts to tell me what the heck is going on and what to do