Steps to reproduce: 

1. enable WiFi HotSpot on phone[A].
2. use phone[A] as MCPE server.
3. connect phone[B] to WiFi of phone[A].

Observed results: 

1. phone[A] world is not visible on phone[B] friends tab.

Expected results: 

1. MCPE should detect if HotSpot is enabled,ad allow other LAN players to join the server.

NOTE: 

1. You need to open ports when others(not LAN) want to join you.
2. this is a LAN game, opening ports is not an issue.

this is not about hosting a server while connected to mobile data internet.

#workaround:

if phone[B] enables his HotSpot and phone[A] running as server connects to phone[B] wifi, the its ok.