GL-AX1800 Flint cannot reach Tailscale full domain name

I have Proxmox with several VMs and LXCs running Tailscale on them. When I go to their full Tailscale domain name, I should be able to reach their admin pages, but all I’m getting is “We can’t connect to the server at …”

For example, I followed this guide to install Home Assistant, then Tailscale inside it. While he can visit the admin page right away, I can’t.

Is there some sort of setting that’s preventing web traffic to reach my Home Assistant VM on my local network?

I’m running the latest firmware on GL-AX1800, Tailscale and Adguard Home are also turned on. Turning them off doesn’t help.

When I go to http://homeassistant.local:8123, it works. I have also set an A record from my domain to my Proxox host’s local IP, and that works too.