Not so darling cat has recently decided that she can't possibly poo in a box! Any ideas why? She has used it fine for the last 3.5years but now she prefers the floor. She is fine in other aspects, no other changes to warrant a trip to the vets, the litter tray was fresh last night before bed. I've tried a different tray, a bugger tray, I've tried less litter, or more litter in the tray, a different location...but nothing! She is 4, so not old age. Uses the tray fine for wee. What can I do?! Thankfully we have tiles so easy to pick up & clean, and she only does next to the tray. Any help greatly received 🙏