So I got a person in another house to work with me via Zoom to troubleshoot. I got us both up and running and able to see one another via Direct Connect but when trying to join each other's games (not at the same time) we were unable. The screen goes black, it hangs for a bit and says it cannot establish network connection or something to that effect. I did see in the Netplay over RetroArch guide, that: "
Troubleshooting
Cannot connect, keeps saying "Connected as Player 1" for the client - If there is an issue and you did not connect, it will either give you an error, or it will just say " Connected as Player 1", and start loading the beginning of the game, which means you did not connect to the host. At this point, both players will need to go back into the Netplay menu, the host will "Stop netplay host", and the client will "Disconnect from netplay host". If using the relay server, the host has to wait about 45 sec or so before trying again (so the game is removed from the netplay host list). You can check by selecting "Refresh Room List" and checking until the host's name disappears (both can see this). (See "Game Desync") I suggest the host waiting to tell the opponent to connect once he reaches the Setup Game Screen. If using Direct Connect, you can re-host almost immediately."
To be fair I did not attempt to "re-host", that will be my next step. In the meantime, are there other known issues as to why this might not be working ? ...tia