Configure https traffic on GSA

It works fine with nginx. Just one issue with /etc/nginx/sites-available/ and /etc/nginx/sites-enabled/ directories. Configs here didn’t work until I put it into /etc/nginx/conf.d/ directory.
Do someone may know why does it happen?

sites-enabled are usually links from sites-available in debian, but it just works if you put file into /etc/nginx/sites-enabled/default

Eero