Nginx Proxy Manager not working on local network

Third party integrations
1

Hi all!

I am running home assistant with the add-on Nginx Proxy Manager.
Using this add-on I want to achieve that I can access my home assistant instance using my own domain using ssl.

I don’t get it working when I am accessing the url on my local network, the page is not loading and according to the logs it looks like I don’t reach the instance at all.
Via the local IPV4 address + port number, I am able to access it.
When I access the url from outside my home network (using Wireguard) it does work as well.

Configuration:
vpn.myexampledomain.com points to my public IPV4 address
homeassistant.myexampledomain.com points to my local ip address 192.168.178.41

VPN outside network: homeassistant.myexampledomain.com :white_check_mark:
VPN turned on while on local network: homeassistant.myexampledomain.com :white_check_mark:
No VPN while on local network: 192.168.178.41:8123 :white_check_mark:
No VPN while on local network: homeassistant.myexampledomain.com :x:

I did some research and I have read about NAT loopback. I have checked this with my internet provider and this is enabled on my modem/router.

The modem does have IPV6 functionality as well but I did not configure IPV6 records to prevent confusion.