Cat urinating out of place.

I’m also writing to reddit, don’t be angry, I don’t know where to go anymore🫩
Hello, we really need help or at least people’s experience, because we don’t know what to do anymore 😭 PLEASE READ IT IF YOU HAVE CATS, maybe you have encountered 🙏🙏

We have a 5-year-old neutered cat who has been periodically urinating everywhere, not in the litter box, for a very long time. Sometimes everything is perfectly fine for a week or two, and the problem seems to be gone, but then it comes back somewhere.
The strangest thing is that he doesn’t seem sick. He eats normally, plays, is affectionate, active, sleeps with us. Also, since August, he has been living with a younger cat, with whom he became very friendly and loves him – they hug, play, wash each other, so we don’t really understand where some big stress could come from.

We’ve tried practically everything:

1. We changed a lot of different litters.
2. We clean the boxes regularly.
3. We use special animal urine cleaners.
4. We have 2 litter boxes (there is no room for more in the apartment😭)
5. We changed the type of litter box from closed to open
6. We went to the Vet, they said everything is fine, but I will go again tomorrow
7. We tried calming pheromone collars and oils.

However, the problem still occurs.
He usually pees near the litter box on the rug, but sometimes just random places on the floor. He has scratched the wall, the cupboard, and constantly urinates on the bed. And the bed is a very strange thing – it never sleeps on a bare bed, only when a cobblestone or some kind of soft fabric is laid on it. It also constantly sizzles on towels or rugs placed in the bathroom. Please advise, help… I don’t know what to do anymore. In the rented apartment, the floor rose due to urine, and the bottom of the cabinet was dislodged. Soon I won’t have money for all the cleaners, dry cleaning, and I’m not talking about what we’ll have to do when we move out and have to buy everything back. Or maybe we’ll go crazy faster, I don’t know. My boyfriend and I don’t smell anything anymore, but I fully believe that the smell here should be terrible.

Any advice and experience would be greatly appreciated. Thank you 🙏