After losing Wifi connection, can not find a network

Since IO5 when I loose a wifi connection (out of range or whatever), the phone (4G) will no longer connect. In the Wifi setting, there are no wifi networks listed anymore, none appear, though there are 4 normally.

Turning off the Wifi and on again does not solve the problem. The only thing that works is turning off the iPhone and then on again.

Any suggestions??