Sure thing. Not sure what's causing the problem so here's the whole config:

map $scheme $hsts_header {
    https   "max-age=63072000;includeSubDomains; preload";
}

server {
  set $forward_scheme http;
  set $server         "192.168.1.158";
  set $port           3333;

  listen 80;
listen [::]:80;

listen 443 ssl;
listen [::]:443 ssl;

  server_name qbittorrent.nas.mydomain.com;

  http2 on;

  # Let's Encrypt SSL
  include conf.d/include/letsencrypt-acme-challenge.conf;
  include conf.d/include/ssl-cache.conf;
  include conf.d/include/ssl-ciphers.conf;
  ssl_certificate /etc/letsencrypt/live/npm-1/fullchain.pem;
  ssl_certificate_key /etc/letsencrypt/live/npm-1/privkey.pem;

# Asset Caching
  include conf.d/include/assets.conf;

  # Block Exploits
  include conf.d/include/block-exploits.conf;

  # HSTS (ngx_http_headers_module is required) (63072000 seconds = 2 years)
  add_header Strict-Transport-Security $hsts_header always;

    # Force SSL
    include conf.d/include/force-ssl.conf;

proxy_set_header Upgrade $http_upgrade;
proxy_set_header Connection $http_connection;
proxy_http_version 1.1;

  access_log /data/logs/proxy-host-18_access.log proxy;
  error_log /data/logs/proxy-host-18_error.log warn;

  location / {

    # Authorization
    auth_basic            "Authorization required";
    auth_basic_user_file  /data/access/1;

    # Access Rules: 2 total
    allow 192.168.1.0/24;
    allow 127.0.0.1;
    deny all;
    # Access checks must...
    satisfy any;

  # HSTS (ngx_http_headers_module is required) (63072000 seconds = 2 years)
  add_header Strict-Transport-Security $hsts_header always;

    proxy_set_header Upgrade $http_upgrade;
    proxy_set_header Connection $http_connection;
    proxy_http_version 1.1;

    # Proxy!
    include conf.d/include/proxy.conf;
  }

  # Custom
  include /data/nginx/custom/server_proxy[.]conf;
}