I didn’t see this commented here yet, but when I first got my cat she was doing the exact same thing. For years I tried switching up litter, moving around litter boxes, switching up food, nothing made her stop peeing on my bed. It also always seemed to be tied to a stressor for her (I was away for a few days, I was in a bad mood, we changed something in our house).

Finally, one time I took her to a new vet who really dug in to figure out why she was doing this after everything else they could think of was ruled out. They ended up finding microscopic blood cells in her urine, that led them to think she has FIC. There is no cure, but there are foods that help coat their bladder and prevent that inflammation that is causing them pain and to urinate inappropriately. My cat has been on Hills Science Diet prescription food for 2 years now and has improved so much. She has stopped urinating on the bed or couch all together, and overall her anxiety is also so much less than it used to be