I am having the same issue. I've been working successfully with Apple Music as a replacement for iTunes since the announcement several months ago that iTunes for Windows was going away. Up until several days ago, one of the things that I appreciated about Apple Music for Windows 10 was that syncing music to my iPhone/iPod was completely problem free, which was a huge improvement over iTunes, which would on random occasions get stuck mid-sync.
I have been trying for 2 days to sync about 30 GB of audio from my Apple Music Library on my Windows PC. Sometimes I get 10% of the way through, one time I got to about 80% complete, but have not been able to successfully complete my sync without Apple Devices shutting down.
I have reset the Apple Devices app on my PC. I have verified my cable and my ports. Short of wiping and reinstalling everything I'm at a loss as to how to fix this.
Does anyone have any ideas?