Crossplatform Session Registration

Goodday Friends
i have 2 Questions or Issues
1- I’m trying to create crossplatform advanced session on LAN working perfect but online i cant find the Session how can i see the same session on all devices ?.
2- I have issue with Server Browser UI on Android When session is exist and found the game crashing …
Note : For Crossplatform session i can Playfab service to Register the session there but its need the Hoster IPv4Address i cant get it in UE4