Virtualmin panel is slow on local network

[pmatt1988]

Operating system:
Ubuntu Server
OS version:
20.04.1

Hello everyone, I’m running Virtualmin on a machine on my local network. When I try to access virtualmin from a connection on the network via the domain name or external ip (ie https://example.com:10000), the UI is very slow, however when I run the admin panel through the local IP (IE https://192.168.1.14:10000), it seems to run normally.

When I access virtualmin from a connection not on the same network, it runs just as smoothly as if I was running locally through my routers IP.

Has anyone ran into this issue and know how to fix it?

[toreskev]

My guess would be this is due to poor implementation of hairpin NAT on your router.
Not all routers support it, though it seems yours might, but it’s far from every manufacturer that gets it right, even in high end gear.
But google your router model and hairpin NAT, maybe something useful comes up.