HTTP2 not working in nginx

Question:

Finally decided to switch to http / 2. Everything is in order on my computer and android smartphone. But I noticed that on the iPhone in Safari and through a proxy, the site simply does not open. White screen. Why is this happening? And is it possible to do non-forced http2 if possible?

limit_conn_zone $binary_remote_addr zone=addr:10m;

server {
    listen 80;
    location / {
        limit_conn addr 10;
        if ($http_host ~ "\d{1,3}\.\d{1,3}\.\d{1,3}\.\d{1,3}") {
            return 444;
        }
        rewrite ^(.*)$ https://jamesjgoodwin.ru$1 permanent;
    }
}

server {
    listen 443 ssl http2;
    server_name jamesjgoodwin.ru www.jamesjgoodwin.ru;

    root /var/www/;
    index index.php index.html;

    client_body_timeout 5s;
    client_header_timeout 5s;

    location ~ \.php$ {
        include snippets/fastcgi-php.conf;
        fastcgi_pass unix:/run/php/php7.0-fpm.sock;
    }

    location ~ /\.ht {
        deny all;
    }

    location ~* ^.+.(js|css|png|jpg|jpeg|gif|ico)$ {
        access_log        off;
        expires           max;
    }

    ssl on;
    ssl_certificate         /etc/ssl/jamesjgoodwin.crt;
    ssl_certificate_key     /etc/ssl/jamesjgoodwin.key;
}

Answer:

Problems with ssl settings. Use ssllabs.com . In the "Handshake Simulation" section of your domain test, you can find behavior for different browsers and operating systems. On the same site you can find the recommended settings for ssl.