Well, the MUSIC alarm works great on the Google Home Mini, but not the Hub.
The REGULAR (non-music) alarm now appears to be working regularly again on the Hub, and it also appears to be turning on at the preset volume, which is nice, and not defaulting to the arbitrary (overly loud) 40% anymore, which is good.
But the MUSIC alarm still does not work at all on the Hub, when set WELL ahead of time (night before). At the alarm time, it lights up the Hub, as if it is about to turn the music on, but never triggers the music, so there is NO sound whatsoever, which of course is a big problem for a wake-up alarm.
One side note: when I tried to just play some music on the Hub (not an alarm, but just play the music), the 1st time it did not work. I said “Play disco music” (lol), and it said it would (confirmed), but it did not start playing (never launched the music/player). So I repeated the request, and the 2nd time it confirmed it (like the previous time), and the 2nd time it did actually play the music. So perhaps the music launcher software has an intermittent problem (and might be the cause of the music alarm issue too?)? Just speculation of course.
One other note: I have noticed that the microphone in the Google Home Hub doesn’t appear to pick up voices as well as the Google Home Mini = you have to be much closer in distance to the Hub, than you did with the Mini (where you could be a lot further away in distance). Not sure what's up, but have seen it discussed online.