HTC one X Wifi connection problem

[omomom]

I am sure that this was posted before, but I am having a problem with my HTC one X. Wifi works normally when phone is unlocked, and when I am browsing the internet. But as soon as I lock the screen internet connection drops but it still shows full strength connection. The only way to use internet again is to turn wifi off and turn it on again. Power saver is off. And also, everything works normally when I am connected to my home network, but problem occures if I connect to any other network besides my home wifi network. I am running a stock android 4.2.2 with HTC sense 5.0. Has anyone found the solution to this problem? Is there any solution?