I dont know what is going on. Just suddenly few hours ago, WiFi suddenly switched to LTE and I put it back on WiFi. Worked like a charm for about 30 minutes then went back to LTE. Since then, It's been switching to LTE at will and I have to manually set back it to connect at WiFi. Ok - Just noticed what the problem is. I set it to WiFi then as soon as I do something data-related (as basic as TEXT MESSAGING, it goes back to LTE).