Starting just today, I can no longer simultaneously play Apple Music on my HomePod, Apple TV, or iPhone/iPad. I now get an error message saying I must upgrade to a Family plan. When the HomePod was introduced, Apple said it would not count against the device limit on the account, as described in this Macrumors article. The same was true with the Apple TV, it didn’t count against the device limit. I often play different music on my Apple TV and HomePod. Also, if I’m away from home and playing music on my iPhone, no one can play music on the HomePod or AppleTV now. I hope this is just a bug and not a change to Apple’s policy, which would be a shameful money grab that I’m afraid is not beneath them.