LAN can't search session by using OnlineSubsystem Null

I am trying package multiplayer shootout project and using the search function but it always return 0 session with successful. But i manage to search session with open 2 instance of game, 1 hosting and another just search. And it will return session that created from the same PC, now the other PC that connected on same LAN will able to find the session.

My issue is second PC will never search any session unless the HOSTING PC open another game instance and do a search session.

Tested method:

  1. no virtualbox
  2. set ping bucket higher
  3. port is open
  4. only using switch for 2 PC as LAN game
    5.try on code and blueprint