We have two cats, both about 7.
One (I'm not sure which) has decided they now like weeing on the sofa. Not all the time, just now and again but regularly enough to be an issue.
They share a litter tray and always have and I have replaced it with a new one since it started. I also use litter liners and replace the litter twice a week (scooping out in between)
I think it started because we got some new cushions which have a kind of raggy texture which he took a shine too.
I've washed the cushions, and the sofa covers but obviously can't wash the sofa pads themselves.
I've tried dettol spray and febreze and some kind of stop cat spray but it's still happening.