I kind of have to agree with divinityxboxoneu's post above. Its nice to see an official response at least acknowledging the issue, but it comes across a little apathetic. Saying they're looking into it, and then claiming its mostly user error (people incorrectly trying to play multiplayer from a singleplayer setup) makes it seem like this is a very low priority problem for them.

I'm no stranger to xbox live, I was playing the original Xbox through Xbox Connect, XBC, before xbox live even existed over 10 years ago, so I'm fairly confident in my ability to setup multiplayer games with the correct settings. No combination of settings has allowed me or my friend (both open NAT) to host or join any online game. We've tried at least a few times each night since the game launched with absolutely zero success.

There is definitely a problem and it is absolutely a game-breaking one for many of us. I don't mind when there's bugs or issues but the developer is completely transparent and apologetic about it. But it kinda seems like Larian is just trying to sweep this under the rug and hope the problem mysteriously resolves itself.