I've had cats in my house (not even indoor/outdoor - only indoor) for more than 40 years. Until last year (after Travis died), I had never ever ever once had a cat poop (or pee) outside the litter box. Then Betty started. Pooping in random places - often right by a clean litter box. Happily, she has not done that in a long while but this morning, I found that Zoey did!! 2 feet beyond the litter box!!! WTF?
I know now that this is not terribly uncommon and that for 39 years I was, apparently, incredibly lucky, but still I wonder why. Nothing has changed everybody is healthy. They have (and use mostly) two gynormous litter boxes that are completely scooped twice a day.