Trying to connect to another network behind my router

So I have 2 routers in my house. My dads witch is hooked up to my modem and mine witch is hooked up to my wall jack and acts as a switch/AP. I have a server in my basement running a hypervisor and was installing radius with one of the VMs and a GUI. when I am on my dads network I can get to the GUI just fine but on my router I can't. I can ping, I have a static route, but I can't get to the GUI on the "Same" network. Does anyone know how to fix this?

P.S. I guess I should mention I have a ivpn setup but I don't know if that matters.

which one of these routers is running OpenWrt? Can you draw a diagram of your network and where the devices are that can and cannot connect to the GUI (also, the GUI of what)?

This may be very relevant, depending on where the vpn setup is happening and what it is setup to do.

My router is running openwrt. give me one sec and I'll make a diagram

here is a simple diagram

Presumably you're making a double-NAT situation with your OpenWrt router. Is that your intention? You could just make it a dumb AP/switch and not have any routing. Then everything would be on the same network.