Hello sakedong,
In order to investigate your problem, can you first tell us what OS and version is installed on the target PC and if you reboot or shutdown the PC ?
Windows 10 has a known issue of not shutting down properly (see a workaround proposed on that website https://www.easeus.com/resource/computer-cannot-shutdown-how-to-fix-windows-10-automatically-restarts.html). Does your problem occur as well when you are not connected with NoMachine to the PC, or not ?