I can no longer control my lights with Gemini assistant. It'll tell me "I can't do that" or "here's how to turn your lights on" or, in at least one instant, play Ellie Golding's Lights at 2x speed.
So now I just use the Google home app and it works as expected.
With Google Assistant (old assistant) I could say "Hey Google, play daft punk" and it would start playing Daft Punk on Spotify.
With Gemini (new assistant) it says "sorry I cannot play music, but here are links to services where you can find Daft Punk albums".
Fortunately at the moment you can still toggle between them. I guess not for long though.