Is it a Female? Imho Female cats can be a pain in the ass.
Sam what kind of material u using in the cat box? Sounds like a big cat is the cat box roomy?
Do u brush the cat?
I give our 2 cats a top of the line dry food which has no fillers they get a endless bowl they never over eat and only poop once a day.
Funny one of our cats goes outside like 6 am spends ALL day outside comes in to poop or pee go figure.
Good Luck
Harsh, but funny.Mrs Ahab brought a farm cat home one time. She thought it was "cute". Sure, it was cute till it decided that it didnt need to go outside to have a leak. It decided that going into the closet where I keep my boots and shoes and pissing on them was a good idea. I tried everything. That damn cat decided it would piss wherever it wanted to.
One morning I caught the bastard doing his business on my hunting boots. It was like he choose them just to piss me off. He was looking at me all squatted up,pissing on my boots with this "whatcha gonna do about it sucka" look on his face. He was taunting me. Daring me to do something about it. He thought Mrs. Ahab was gonna protect his pissy ass no matter what. Well, guess what you effing piss puss, you thought wrong.
I took him outside and put two in his hat. Sent him to the big catnip farm in the sky. Piss heaven. No regrets.