My smart home device supports both the Alexa.BrightnessController and Alexa.PowerLevelController interfaces but requests for power setting come as set brightness under the Alexa.BrightnessController namespace.
Alexa, Set MyDevice brightness to 20% -> Alexa.BrightnessController, Set Brightness - as desired
Alexa, Set MyDevice power to 20% -> Alexa.BrightnessController, Set Brightness - not what I want.
If I remove the Alexa.BrightnessController from the device interface during discovery then I get the expected Set Powerlevel requests.
A similar thing happens with the Alexa.PercentageController (i.e. brightness always wins).
I need to support both power level and brightness (it's a fan with lights, so fan speed and light level).