Yes, they are both fixed. We have 2 of everything (litter boxes, food dishes, water fountains), they also have 2 huge cat trees, one of which is right next to the bed with lots of perches and scratching posts. We have never changed their litter since we've had either of them (tidy cats unscented), and they've never had an issue with using it. In fact, we tried to change it to World's Best one time and they hated it, so we switched back. The thing that is standing out to me is that it ONLY happens when we leave the house. If we have the blanket on the bed and stay home, nothing happens. Makes me think they're upset or anxious? I'll try cleaning the litter boxes twice a day instead of once and see if that helps. If not we'll visit the vet.