Issue with change protocol after 301 redirect (Nginx/BitrixVM/CentOS6.5)

I'm using following settings:

s1.conf

# Default website
server {

    listen 80;
    server_name test.com www.test.com;
    return 301 https://test.com$request_uri;  # enforce https

    server_name_in_redirect off;

    access_log /var/log/nginx/access.log main;
    error_log  /var/log/nginx/error.log warn;

    proxy_set_header    X-Real-IP        $remote_addr;
    proxy_set_header    X-Forwarded-For  $proxy_add_x_forwarded_for;
    proxy_set_header    Host $host:80;
    proxy_set_header<   X-Forwarded-Host $http_host

    set $proxyserver    "http://127.0.0.1:8888";
    set $docroot        "/home/bitrix/www";

    index index.php;
    root /home/bitrix/www;

    # Redirect to ssl if need
    if (-f /home/bitrix/www/.htsecure) { rewrite ^(.*)$ https://$host$1 permanent; }

    # Include parameters common to all websites
    include bx/conf/bitrix.conf;

    # Include server monitoring locations
    include bx/server_monitor.conf;
}

s1_ssl.conf

# Default SSL certificate enabled website
server {
    listen  443 default_server ssl;
    server_name test.com;

    # Enable SSL connection
    include bx/conf/ssl.conf;
    server_name_in_redirect off;

    proxy_set_header    X-Real-IP   $remote_addr;
    proxy_set_header    X-Forwarded-For $proxy_add_x_forwarded_for;
    proxy_set_header    Host        $http_host:443;
    proxy_set_header    X-Forwarded-Host $http_host;
    proxy_set_header    X-Forwarded-Proto https;

    proxy_set_header    HTTPS       YES;

    set $proxyserver    "http://127.0.0.1:8888";
    set $docroot        "/home/bitrix/www";

    index index.php;
    root /home/bitrix/www;

    # Include parameters common to all websites
    include bx/conf/bitrix.conf;

    # Include server monitoring API's
    include bx/server_monitor.conf;

}

When I try link http://test.com/xyz/ or https://test.com/xyz/ all is OK. But when I try link like http://test.com/xyz or https://test.com/xyz I'm get 400 Bad Request, The plain HTTP request was sent to HTTPS port

This curl output:

curl -I -k https://test.com/xyz
HTTP/1.1 301 Moved Permanently
Server: nginx/1.6.2
Date: Mon, 22 Feb 2016 09:13:28 GMT
Content-Type: text/html; charset=iso-8859-1
Connection: keep-alive
Location: http://test.com:443/xyz/
X-Content-Type-Options: nosniff
X-Frame-Options: SAMEORIGIN

Why protocol change to http?

you forgot to say that the reference to http://test.com/xyz is directory.

what is evil: mod_dir

A "trailing slash" redirect is issued when the server receives a request for a URL http://servername/foo/dirname where dirname is a directory. Directories require a trailing slash, so mod_dir issues a redirect to http://servername/foo/dirname/.

and for him "HTTPS on" not working, scheme https: // not be

what should be done:

1) nginx configurations do not touch anything

2) in httpd configurations for your domain, example: /etc/httpd/bx/conf/bx_ext_site.local.conf

where string contains name your server, example: ServerName site.local

supplemented by the following: https://

to be so: ServerName https://site.local

that's all you need

it works without any redirects

meaning the problem is hidden in the manual http://httpd.apache.org/docs/2.2/mod/core.html#servername

Sometimes, the server runs behind a device that processes SSL, such as a reverse proxy, load balancer or SSL offload appliance. When this is the case, specify the https:// scheme and the port number to which the clients connect in the ServerName directive to make sure that the server generates the correct self-referential URLs.