I have had two devices that did not like my cheap router.
One kindle and one pc. It liked other routers running the same settings.
A friend of mines s4 did this as well with his router.
It is not your device I'm blaming it is the router+device I am blaming.
Either take the suggestion or don't but it would be my first go to.
Sent from my GT-P3110 using xda app-developers app