GL.iNet NGINX Reverse Proxy

Situation: I already use a nginx reverse-proxy with Let's Encrypt SSL to access all my internal sites. However, after getting my GL.iNet GL-MT6000/Flint 2 router, I had issues access its various pages and services.
I got to learn about WebSockets and the changes I needed to make to my old configurations.

---

#
# /etc/nginx/sites-available/$server_name
#

# Redirect Default HTTP to HTTPS:
server {

 server_name router.domain.local;

 listen 80;
 listen [::]:80;

 return 301 https://$server_name$request_uri;

 error_log /var/log/nginx/error-$server_name.log;
 access_log /var/log/nginx/access-$server_name.log;

}

# Redirect LuCI HTTP to HTTPS:
server {

 server_name router.domain.local;

 listen 8080;
 listen [::]:8080;

 return 301 https://$server_name:8443$request_uri;

 error_log /var/log/nginx/error-$server_name.log;
 access_log /var/log/nginx/access-$server_name.log;

}

# GL.iNet WebSockets Router:
server {

 server_name router.domain.local;

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

 # nginix needs cert & chain combined
 ssl_certificate /opt/certs/acme/domain.local/fullchain.pem;
 ssl_certificate_key /opt/certs/acme/domain.local/privkey.pem;

 # nginx ciphers and protocols
 include /opt/certs/ssl-options-nginx.conf;

 location / {

  proxy_pass https://192.168.1.5:443;

  # nginx standard proxy settings
  include proxy_params;

  # enable websockets settings
  proxy_http_version 1.1;
  proxy_set_header Connection "Upgrade";
  proxy_set_header Upgrade $http_upgrade;

  # reduce websocket reconnect errors in router log
  proxy_read_timeout 1d;

 }

 error_log /var/log/nginx/error-$server_name.log;
 access_log /var/log/nginx/access-$server_name.log;

}

# Advanced Settings / LuCI
server {

 server_name router.domain.local;

 listen 8443 ssl;
 listen [::]:8443 ssl;

 # nginix needs cert & chain combined
 ssl_certificate /opt/certs/acme/domain.local/fullchain.pem;
 ssl_certificate_key /opt/certs/acme/domain.local/privkey.pem;

 # nginx ciphers and protocols
 include /opt/certs/ssl-options-nginx.conf;

 location / {

  proxy_pass https://192.168.1.5:8443;

  # nginx standard proxy settings
  include proxy_params;

 }

 error_log /var/log/nginx/error-$server_name.log;
 access_log /var/log/nginx/access-$server_name.log;

}

# AdGuard Home:
server {

 server_name router.domain.local;

 listen 3000 ssl;
 listen [::]:3000 ssl;

 # auto-redirect to https to prevent http error:
 error_page 497 https://$server_name:3000;

 # nginix needs cert & chain combined
 ssl_certificate /opt/certs/acme/domain.local/fullchain.pem;
 ssl_certificate_key /opt/certs/acme/domain.local/privkey.pem;

 # nginx ciphers and protocols
 include /opt/certs/ssl-options-nginx.conf;

 location / {

  proxy_pass http://192.168.1.5:3000;

  # nginx standard proxy settings
  include proxy_params;

 }

 error_log /var/log/nginx/error-$server_name.log;
 access_log /var/log/nginx/access-$server_name.log;

}