The 15.5.1 update fixes issues where music could stop playing on Apple’s HomePod or the Siri speaker may lose its deep bass after a short time.
Users complain of HomePod music playback issues
Does music on your HomePod stop playing after a short time? Is the Siri speaker exhibiting intermittent bass loss? Well, there’s now a fix for those annoyances!
You could argue that it doesn’t matter whether a smart speaker stops playing music on its own. We beg to differ: Don’t forget that the HomePod’s primary purpose is to play music and serve as an Apple Music accessory. Apple hasn’t yet publicly commented on this annoying issue beyond a short acknowledgment in theHomePod software 15.5.1 release noteswhich confirm that “HomePod software version 15.5.1 addresses an issue where music could stop playing after a short time.”

The much-needed fix for interrupting music playback arrives following the earlier HomePod software 15.4.1, which fixed an issue whereHomeKit-compatible smart home appliances wouldn’t respond to Siri voice commands.
How to install HomePod software 15.5.1
To manually download and install HomePod software 15.5.1 to your Siri speaker, use the Software Update function in the Home app on your iPhone, iPad or Mac.
If you use multiple HomePods in your household, you’ll also see an “Update All” button so you may choose whether to install the new software on specific speakers or all of them at once. By default, the automatic updates option is turned on but you can turn it off in Software Update if you’d like to manually apply updates. The Software Update screen also shows whether your HomePod is already up to date and which software version it’s currently running. Just be sure not to unplug your HomePod while it’s being updated or you may be ended up with a bricked speaker.