Hi, I am using a Factory Unlocked iPhone 4S on 5.1.1. I have been facing issues with Personal Hotspot connectivity through WiFi. The hotspot WiFi availability is unpredictable. It is not detectable in the list in the list of available networks. Have been able to connect at times but by switching on & off the personal hotspot several times. Whereas, I get connectivity through bluetooth & usb. My device came with 5.0.1 and had the issue with that too. Pls assist.