Problems accessing hosted services within network
I've set up a network, where I'm hosting a site with a domain.
All Omada hardware is connected after the ISP router. The ISP router is configured to DMZ to the Omada router.
Port 80 and 443 are redirected to the server that's hosting the site.
I've set up a pi-hole for local DNS to point directly to the webserver.
Accessing the website outside the network works great.
But when accessing the site from inside the network, I'm just shown the web UI of my ISP router (webserver isn't accessed). Pinging the domain shows the correct IP address for webserver.
This setup worked perfectly fine with my previous Asus router, which was set up in the same way. I'm suspecting some hairpin NAT issue, but I'm not sure. I'm really not sure how to proceed debugging this issue.