I get this message from my really simple sll and pro multisite plugin
How can this be fixed?
Really Simple SSL has detected NGINX as webserver. The HSTS header is set using PHP which can cause issues with caching. To enable HSTS directly in NGINX add the following line to the NGINX server block within your NGINX configuration:
add_header Strict-Transport-Security “max-age=31536000; includeSubDomains” always;
For more information about NGINX and HSTS see: HTTP Strict Transport Security and NGINX
https://www.nginx.com/blog/http-strict-transport-security-hsts-and-nginx