What were the health reasons your cat peed outside the litter box?

He is very cute when he sleeps, but… He is 3 years old, sterilised. We tested urine, blood, heart - everything is good. We have 3 litter boxes, tried various litters, nothing changes, he keeps peeing on sofa(sometimes poops), or if we baricade sofa, he will pee on the floor, doesnt matter if the litter box is right there. We clean boxes daily. He is very social, we have two cats, he peed before the second arrived and is peeing now, nothing changed. We work from home so we really spend lots of time with him, so he does not have a separation anxiety. We think it could be something health related, but we do not know what to look for anymore. Any story on how you fixed peeing everywhere solved is appreciated, maybe we will find something or we are missing something