Find Sessions Consistently Returning Results Length of 0

It appears that as of 4.15, there is an issue with creating/joining sessions. The attached test project worked fine previously in 4.14, but now is unable to join sessions.

The user has stated:

The only way I get a result is with "Use LAN" set to true on create session,

1. Open the attached project in 4.15
2. Play in New Window with 2 Players
3. Press Create to create a session
4. On the client, Press Join to attempt to join the session

Result: Failed to join session

Expected: Client would join session successfully

Multiplayer blueprint problems on mac (Multiplayer Shootout and Tutorials)