You might want to relocate the litter box or add another.
Cats value their privacy. Litterbox is in the bathroom and I keep the light off. Never had issues
The rule for litter boxes is N+1 where N = number of cats.
Never had a problem when following this rule, except when one kitty got a bladder infection.
A quick google followed by clicking on the first link and uncritically reading the first sentence tells me there's over 1 billion cats in the world. I don't think I can afford that many litter boxes
We have 4 cats with 4 boxes and they do just fine
That said... 4 cats is too many and I don't recommend anyone get this many unless you are a cat sanctuary
We have 4 and two litterboxes. No issues with them doing their thing. I have had it recommended we need more litterboxes, but since there are no issues, I don't really see the point. That being said, we religiously clean those twice a day, so I suppose that helps. And on the point of 4 cats, I agree, it's a bit much. We had two and then last year we found two kittens on the street (not at the same time), one scroungy as hell and the other one had a gaping wound. We nursed both back to health and then didn't have the heart to give them away, so yea, that's how that went.
Good tips in the comments - although in my experience sometimes it just doesn't work. I've got 3 litter boxes for one cat, they are accessible to him, private, and clean. He still poops on the floor when I'm not at home (or asleep).
Animals can have behavioral issues just like people.
