I newly created a save file, and repeated booting to see if those issues persist.
Surely the volume of sound is not saved. But I haven't been able to reproduce the issue of the hwclock setting.
When I booted with the former save file and rebooted into another puppy, the clock needed to be adjusted.
So it is conceivable that I may have done something wrong to the former save file, though I don't remember doing anything related to the hwclock setting.
I feel sorry to have made a fuss.