Quoted from jsa:We'll troubleshoot this more tomorrow, but one thing we've noticed is that machines that were paired_ beforehand, prior to a purchase, and never disconnected, sometimes run into this issue. With Scorbitrons, it automatically pairs to the new machine. With JJP, we haven't implemented that yet on the JJP side, but it seems like an obvious choice, along with the ability to "unpair" a machine from it's previous owner. Stay tuned for more on that later.
I'm running to this issue with a game I purchased from another owner (GnR). Everything is working with the networking, and Scorbit shows connected in the game settings menu, but I cannot add it to my home location.