Mullvad Wireguard VPN configuration isssues on Raspberry Pi 4B

[mk24]

The issue here is the same as this one:

Need help with openvpn configuration on OpenWrt router

The problem here is that you're running the travel router as a dumb AP, but following instructions as if it were a LAN->WAN router. In the dumb AP, wireless users are on LAN and they are bridged directly to your house main router. They'll never be aware that they should route through the VPN instead. They really can't, since you'd need a DHCP server to tell them to use your router as the default gateway, and that will interfere with other devices on the LAN that should get DHCP instructions t…

Presently you have both Ethernet ports in the br-lan bridge. So LAN users can't be routed through the VPN.

Create a new network called exactly wan with eth0 as its device (remove eth0 from the br-lan ports list). This network can have proto DHCP, or a static IP on your upstream network. Change the LAN IP to something that does not overlap the upstream network and turn the DHCP server on LAN back on. Now there is routing in effect, and you can readily route from lan->vpn instead of lan->wan.