Adult cat with issues

[Katiecoooooo]

We rehomed a cat a month ago who we were told had no issues with using the litter tray. Well he has only used the litter tray to wee in and he has also had a wee on carpet and my bed! It is always a hunt to find where he has pooed and it is always in a different place. We have feliway plug ins and a herbal powder which is supposed to relax if it is stress. We have moved the litter tray, changed the litter and covered it over but the house is beginning to stink. Does anyone have any advice?

The main or original litter tray is a large one with the sieve thing from pets at home and the others are largish too without the sieve just boxes. He has a large habitat Come scratch post with 2 dens he likes to sit in. He likes to sit on the back of the sofa which gives a view of the door. Went to bite dd today....he will do something to make us think he is starting to settle followed by big backward step.