A nasty bug started popping up on Google Home units around December 25th that would make the units either refuse to play music entirely from some sources or play one or two tracks and then stop, and it seems that Google may have put out a fix, but if they did, it didn't do much good; the bug is still alive and well for many users. A quick look at the Google Product Forums thread for the issue tells the tale. It all began on December 25th, when user JohnnyG1 created a thread to say that his Google Home unit would play music sporadically from Google Play Music, if at all, while other services seemed to work without any issues. The following day, Googler Christina Phan posted a reply saying that Google was working on a fix, and then another reply later asking those still affected to continue replying. The replies are still coming.
The issue has affected a large number of users, and seems to have even spread to Chromecast users, albeit in far smaller numbers than those whose Google Home units have been affected by the glitch. Many of the people on the Google Product Forums topic for the issue are also reporting that the bug is spreading to other music sources and services, or is even becoming indiscriminate about the source and stopping any and all music playback on their devices, though audio playback from non-music sources, such as the device's own talkback voice don't seem to be affected thus far.
The timing of the bug could not have been worse, as many users noted; no small number of users were unboxing new Chromecast and Google Home units for Christmas, just in time to be hit by the bug and watch their expensive and smart new toy struggle to do something a $10 device can do with no issues in front of family and friends. For the moment, Google seems to have taken no further action, and no other Google representatives have posted on the topic as of this writing. Thus, the reports continue to rack up as the bug hits more and more users.