I\'m receiving a message \"Failed to load resource: The network connection was lost.\" in my application, which uses ajax requests to get content from
One of the reasons why it might happen is the way Safari handles some SSL certificates (mainly, LetsEncrypt). The solution is to put the line:
ssl_session_cache shared:SSL:10m;
to your nginx config.
Source: https://community.letsencrypt.org/t/apple-safari-browsers-fail-to-connect/3731/3