Xbox Live connection issue when running two machines on the same LAN

Verification builds: 1.2 / 464771

Summary: Unable to connect to an multiplayer game via Xbox Live when running machines on the same local network.

Impact: Can't connect to the world.

Repro Steps:

• Have two Windows 10 machines running version 1.2 (464771)
• Both machine must have an internet connect but must also be on the same local network (LAN)
• Make sure both machines are logged into different Xbox Live accounts that are friends with each other
• Start a multiplayer game on one machine (Xbox Live Settings shouldn't matter)
• On the other machine try and connect to the multiplayer game

Observed Results: The second machine isn't able to connect to the world and is shown the following error:

Unable to connect to world

Expected Results: The second machine should connect to the world.

Screenshots/Videos attached: No