I had it occurring (almost?) nightly between 3:00 and 4:00 a.m. for two of my Naim streamers but not the third. According to the notification, I, myself, was doing this in my sleep.
For a while it was even worse because the option to return the streamers to their rooms disappeared.
Naim support was able to duplicate the issue, but it could not provide a fix.
These were only some of the problems I had with Google Home. I posted on my frustrations in this forum many times. Ultimately, I dumped Google Home and switched to Alexa