You’re not the only one with this issue, please have a look at this discussion (only German).
So I guess this is a bug in the Fibaro app. I have 2 Fibaro Walli Controller in use, but battery powered, and I can’t change the LED color also. Of course, not via flow but by changing the LED settings in the advanced device settings after waking up the device.
Could you please contact Athom, hoping that they fix this issue.
