Issues with the latest patch

So I have downloaded the latest MCC patch that went out late August. I have played some games and at the time everything seemed to be working as it was intended. Since the weekend I have had issues relating to party chats and game searches only relating to MCC.

My girlfriend and I partied up and she joined my game lobby. Separate Xboxes (1x and a 1s), same house, with a wired connection on both. Our ports have been forwarded on our router. I have hard restarted xbox as well as the internet connection several times. For whatever reason when we try to search for a game together the game itself crashes and our party encounters an error every single time we try. Great game with a lot of great memories but it’s disappointing when you can’t share a passion with a loved one because of the ongoing issues surrounding the game itself since release.

Does the issue with party chat happen only on MCC or across all games?

EDIT: Just ripped this from a support forum. Try the steps below. Seems more like a home network setting problem than MCC issue.

1 - do not use port forwarding anywhere .
2 - enable UPNP (router).
3 - on each xbox go to use static IP, alternative port and mac address
4 - make sure each xbox is using a different port.
5 - clear mac on both xboxes, and then restart the router.
6 - bingo, all will work.