Airplay connection solved for RB50 guest network

I got my RB50 for 3 years.  Ever since then the airplay/screen mirror function failed for my iphone, and other android device.

I always thought it might be my iphone, until recently got my iphone airplay working perfect in friend's house.

So I googled and change the setting in "orbilogin.com" showed on RB50 label. 

I choose the option in Guest Network "allow guest see each other", and airplay works.