Status updates from Ikea Trådfri drivers (dimmable transformers)

You were a bit too fast.
The main change in Homey V5.x is the optimization of the ZigBee integration and the change from SDK2 to SDK3 (I think I’m not a programmer).
As long as the old ZigBee apps haven’t been updated to SDK3, but you have already installed Homey FW v5.x, the apps won’t work anymore. Maybe you should have checked the forum first.
If you want to know the status of the Aqara app, you can follow this post: