Hi,
After computer restart, the previous remote session was supposed to be terminated and released. Also according to below thread, it is expected behavior to choose update and restart without bypassing them.
But you may also take a look at on the suggestion of SCCM and WSUS mentioned:
https://social.technet.microsoft.com/Forums/en-US/57a51002-2b63-4468-8d99-0b45be66edf2/automatic-upgrade-windows-10-to-newer-version-1703-without-user-interaction?forum=winserverpowershell
Hope this helps and please help to accept as Answer if the response is useful.
Thanks,
Jenny