My cat is not pooing in her litter tray anymore. She will wee in there, but won’t poo. Her litter type hasn’t changed, we always clean the poo out immediately (and always have) and change the whole thing once a week so it’s not a cleanliness issue. We have 4 trays for two cats and they have always used two each (e.g. she uses two and our other cat uses the other two - they don’t share). She goes in different places each time, there’s been no household changes and no stress for her. This has been for the last 3 or so weeks. Any suggestions?