Adopted cat litter issues

[ShineyBlackShoes]

I adopted a cat whose around 2 or 3. He’s been neutered and has generally settled in well.
He started off using his litter for wee but pooped just outside. Then he has stopped. He does his poo in a box but doesn’t cover it. However he now does he wee randomly on the carpet. A couple of times he’s been in the same place, but other times it’s anywhere.
He has refused to use Worlds best cat litter and anything that’s clay/ash. He has used silica once, and is using cardboard pellets for poo. He did wee in that once but only once.
He has litter trays of different sizes and size doesn’t seem to the issue.

Help; I’m currently confining him to my living room and kitchen area which has a laminate floor in the hood that works.

I’ve only had him 3 weeks and he’s been seen by the vet so has no medical issues.

I’d welcome any advice.

So you have two trays currently and they both have the paper pellets? And he is only using one and that's for poo only?

Do you have a cat flap? After three weeks he can start to go out. That might in itself resolve the issue.

Our new cat has used the litter tray but prefers the plant pots. Could you make an earth tray?

Yes, 2 trays with the same litter and he’s only using 1 and that is for poo. He has another 2 trays: 1 silica which he’s used once for wee, and a towel in a bowl which is the closest to a carpet I can do.

Don’t have a cat flap and can’t due to the type of doors I have. But he’s an indoor cat anyway (apparently). It works better for me that he’s indoor anyway.

Not thought about soil: I might give that a try; thanks

I would look at the location of the litter trays as well. Are they in a private enough location or directly in front of windows or in busy areas of the home?

The area is fine for his poo-ing so cant see why wee would be different. Really odd