People have been complaining about this problem for some months now. It also keeps happening with my HomePod minis. They are also connected to an Apple TV 4K as a pair. I physically switch off the three of them and the Wi-Fi on my router every night or when I leave my home. I don't like wasting energy for nothing when I don't need it, and also think that it's good to switch off my Wi-Fi when it isn't needed. So, whenever I want to use the HomePods, I switch on the power switch on the power bar they are connected to (the Wi-Fi has usually already been on for a while in these cases and works fine with all other equipments, many of them from Apple as well), and they presumably boot from scratch. During this new boot sequence they should set up everything correctly if the software installed in them would be coded correctly. But it doesn't work. Every time Siri will respond with "sorry, there is a problem with Apple Music" when I ask her to play some music.