According to a recent thread on Reddit (via 9to5Mac), users were discovering that they are no longer able to play separate songs from Apple Music on the HomePod and iPhone. The post reads, “Today I discovered an issue: When I tried to listen to different music on my iPhone, while my wife was listening on the HomePod in the living room, the music on theHomePod stopped. If I start music on myHomePod my iPhone stops and tells me that a different device is using the account.”
The user then reached out to Apple who then informed them apparently parallel streaming was a bug that has since been fixed, which means that separate streaming on multiple devices will no longer be possible. There is a catch, however, and that is users will need to create a Family membership if they wish to be able to stream on multiple devices at the same time.
This is based on Apple Music’s terms and conditions where it says, “An Individual Apple Music membership allows you to stream on a single device at a time; a Family membership allows you or your Family members to stream on up to six devices at a time.”