I'm getting the same problem too. It started the night I upgraded to 16.
I was able to trace it to a file size issue. After connecting to VPN, I use robocopy to create an offsite backup. When it gets to a 4GB file, it disconnects halfway through.
After reconnecting to VPN and rerunning script, it will complete, but it means I have to do it manually now. @Meraki any ideas??