We are using an Asus router with built in openVPN to remotely connect to the local network on which a windows machine runs. We then use Microsoft Remote Desktop to facilitate the connection of remote to local windows machine.
Connecting to the VPN with both IPv6 and IPv4 works. However making the connection from remote machine to local windows machine only works over IPv6 when connected to the vpn.
At first I thought there might be a device on my remote network colliding with the IPv4 of the local machine so I assigned an IPv4 I knew wasn't on my remote to the local windows machine. The issue still persists.
a few things I've tested:
pinging remote to local over IPv6 times out but Microsoft Remote Desktop still connects
pinging remote to local over IPv4 times out and Microsoft Remote Desktop doesn't connect
pinging locally to local works and Microsoft Remote Desktop works as well.