Why Can't I Access My Home Assistant Remotely via Nginx Proxy Manager on Raspberry Pi 3?

Question

I'm facing difficulties setting up remote access for my Home Assistant on a Raspberry Pi 3. Feels like I've tried everything, but can't seem to get it to work. Would appreciate some help!

My setup

• Raspberry Pi 3 Model B
• Home Assistant installed in a Docker container, updated to latest version
• Nginx Proxy Manager add-on installed for reverse proxy configuration
• Domain hosted by my ISP pointing to my router's WAN address
• Fetching and renewing SSL certificates using DNS challenge against DirectAdmin, with the SSL files fullchain.pem and privkey.pem located in the /ssl directory on HA

Current Status

• Both the local Home Assistant address (homeassistant:8123) and my domain work within my network. But not outside the network of where my HA installation is running on.
• LAN/WAN Port Forwarding: 80/80, 81/81, 443/443, all directed to the Home Assistant IP.
• No ports blocking on my router
• No firewall blocking

Home Assistant Configuration

In configuration.yaml:

http:
  use_x_forwarded_for: true
  trusted_proxies:
    - 192.168.10.178  # Home Assistant IP
    - [My_Public_IP]  # My Public IP
    - 172.30.32.0/23  # Docker address
    - 172.30.33.0/24  # Docker address
    - 172.30.32.3     # Docker DNS address
    - 127.0.0.1

Nginx Proxy Manager Configuration

I have created a proxy host using the Nginx Proxy Manager add-on. In the configuration, I have chosen the following settings:

• Protocol: http
• Destionation: mydomain.se
• Port: 8123
• Websocket Support enabled
• SSL: DNS Challenge DirectAdmin

What I've tried

I've tried several troubleshooting steps, including different port forwarding configurations, ensuring there are no firewall issues, and validating my Nginx Proxy Manager configurations, but I'm still facing issues.

Error message

One recurring error message in the Nginx Proxy Manager logs is:

connect() failed (111: Connection refused) while connecting to upstream, client: 
192.168.10.119, server: nginxproxymanager, request: "GET /api/ HTTP/1.1", upstream: 
"http://127.0.0.1:3000/", host: "homeassistant.local:81", referrer: 
"http://homeassistant.local:81/"

I'd appreciate any insights or suggestions on what might be causing this issue and how to resolve it. Please let me know if there's any additional information needed.