...Ok. Just made it work. It missed something I did not even include here (it was tls tweaks I thought unimportant on the issue)
this snippet :
""
ssl_protocols TLSv1.2;
ssl_prefer_server_ciphers on;
ssl_ciphers 'ECDHE-RSA-AES256-GCM-SHA384:ECDHE-RSA-AES256-SHA384:ECDHE-RSA-AES256-SHA:ECDHE-RSA-CHACHA20-POLY1305';
ssl_ecdh_curve secp384r1;
ssl_session_cache builtin:1000 shared:SSL:10m;
ssl_session_timeout 1d;
ssl_session_tickets off;
ssl_stapling on;
ssl_stapling_verify on;
add_header Strict-Transport-Security "max-age=15768000; includeSubdomains; preload";
add_header X-Frame-Options DENY;
add_header X-Content-Type-Options nosniff;
""
I don't understand why this solve the problem, but it does. Maybe the tickets off ? No idea.
this snippet :
""
ssl_protocols TLSv1.2;
ssl_prefer_server_ciphers on;
ssl_ciphers 'ECDHE-RSA-AES256-GCM-SHA384:ECDHE-RSA-AES256-SHA384:ECDHE-RSA-AES256-SHA:ECDHE-RSA-CHACHA20-POLY1305';
ssl_ecdh_curve secp384r1;
ssl_session_cache builtin:1000 shared:SSL:10m;
ssl_session_timeout 1d;
ssl_session_tickets off;
ssl_stapling on;
ssl_stapling_verify on;
add_header Strict-Transport-Security "max-age=15768000; includeSubdomains; preload";
add_header X-Frame-Options DENY;
add_header X-Content-Type-Options nosniff;
""
I don't understand why this solve the problem, but it does. Maybe the tickets off ? No idea.