I am trying to render a content "test". No sample data and script.
In jsreport studio it is taking 20 second of average.
This is a very long time and the first problem to solve.
What is your hw machine setup? Even a single CPU machine needs to handle it in a one second.
Do you run in docker? What if you run without nginx, do you have the same results?
I see you posted one log where it looks you run on Linux and one when you run on Windows.
I guess windows is just a dev machine. There you have also the same performance problems?