@Jamie … but no matter how I tried to reproduce it over again, I couldn’t. I only can see that when Nginx feature is disabled, config file is getting deleted but its .lock file stays in place. That is the only bug I see at the moment.
unfortunately i deleted vm and started again with new fresh installation so i do not have the files. it was on fresh debian 10 installation so i suppose nginx was the latest version. i am trying again with configuration in case of a problem i will come again with conf files.
At the moment, you will hit the same problem, unless manually update Virtualmin-Nginx module before creating virtual-server.