It’s an issue with the app, here is a (Dutch) thread about the same issue. Athom’s solution is that you need to fully and completely reset your Hue setup first, then add it back to Homey.
It all smells like a load of BS to me because the issues started with an update of the Homey Hue app, and other platforms aren’t affected in any way (like you already found out with HA), but that’s the official statement of Athom.
