Halo: Combat Evolved PC Co-Op unplayable.

I have been trying to connect to a friend that is in another country that I recently have been playing Halo: Reach with little to no issues. Now today after the patch introducing we naturally thought we could play together. Nope, before we even get past the load screen it returns us to the previous menu abruptly and states: “Connection has Been Interrupted” or something along those lines. We tried again and again after running numerous random tech steps and nothing, absolutely nothing has worked. It appears after a short read on Reddit, and the forum here others have recently been dealing with the same issues randomly both pre-and post patch on Reach. I would really like to know what is going on as it is really hard to love a game so much, and to keep seeing it riddled with problems and shortcomings on the PC.