I have a problem with internet connection on my SG4. Specifically only Wi-Fi.
For once, Samsung Apps/Hub says "No network connection" when I open them up and it doesn't connect, but if I turn Wi-Fi off and use 3G, it works. Same with WhatsApp, which is acting very weird. In a group chat I try to download a video someone sent, and it says "Download failed. Try again later.", but if I turn off Wi-Fi and again, use 2/3G, it starts the download of that video without any problems.
The Wi-Fi itself is not a problem I think. Other than those 2 apps and all Samsung connections, everything else works on Wi-Fi. YouTube (though sometimes it also loses connection), Twitter works excellently, DropBox, SpeedTest, Tumblr.... everything else works just fine.
It's also sometimes disconnecting/connecting randomly from my Wi-Fi connection. And it used to be a perfect connection before I tried flashing latest ROMs.
My phone's info:
ROM: Goldeneye v30
Knox warranty void: 0x1
My Wi-Fi router: Linksys WRT54G2