I've spent a couple of days trying, and eventually succeeding, in installing nopCommerce 4.40 on a Hyper-V instance in Windows 10 Pro. I'm a newcomer to Linux and a slow learner by all accounts hence why it took so long .
I found that on restarting the Hyper-V instance I received a 'Bad Gateway' error from nginx.
The status of the nopCommerce440.service was showing as disabled and the fix, in my case, was to issue the command
sudo systemctl enable nopCommerce440.service
I hope this proves useful to anyone else running into the same problem.