Since Whisker seems to have recently botched up connectivity for Litter Robot 3 models, I have developed a Litter Robot Proxy app to allow for local monitoring of Litter Robot 3 devices. It uses MQTT for intercepting status messages and requires a local DNS rewrite (AdGuard Home or Pi-hole work great for this). It does NOT allow for control (manual cycles, for example), but it at least allows you to track waste levels and activity.
You can check it out here: GitHub - adamjthompson/litter-robot-proxy-app: Proxy app for intercepting traffic from Litter Robot 3 devices and passing it to Home Assistant using MQTT for local monitoring. · GitHub
My only current issue with it is that my robots seems to go offline occasionally. I have them on smart plugs and I use an automation to restart them when that happens. It's not ideal, but it works. I don't know yet if the issue is from the proxy or something else, perhaps on Whisker's end.