I'm guessing, because I had to roll back the last W10 updates and then pause updates when KB5000802 crashed my (and others) printer. I had a look and noticed that the update had installed again so I suspect the sound stopped working after that. The annoying thing is that it occasionally works. It's hard to tell as mostly I'm doing something when I'm in front of the computer but it maybe that the sound only happens when it is idle. I've checked all the notification settings and they are on, I've check focus assist and it is off. Any ideas, I've run out of mine.