It seems like you’ve misunderstood this feature of Google Assistant. Now Playing is a pixel exclusive feature that works in the background without triggering assistant and shows the currently playing song on the lock screen and always on display. It seems like OP is trying to trigger this feature from the foreground? Which I think would be a good feature but I doubt Google would let any phone use this cause profit. So I guess this is still fitting for mildly infuriating lol

Now Playing is a pixel exclusive feature that works in the background without triggering assistant and shows the currently playing song on the lock screen and always on display. It seems like OP is trying to trigger this feature from the foreground? Which I think would be a good feature but I doubt Google would let any phone use this cause profit. So I guess this is still fitting for mildly infuriating lol