in my area, the 3g network is slightly weaker than 2g, this is the main cause making the phone keep prefer 2g network even the 3g already good enough for connection. Any suggestion?
The Lumia ancestor Nokia N9, has the good gene which allow the network setting to be Dual mode, GSM, and 3G, but its successor has dropout the good gene.
That's EXACTLY the setting I needed. Thank you very much!!
It used to be ##3282#. Now it's just ##3282 and call. Try it.
After dialing that code, look for the three dots (...) and then hit "settings". Works on my 520 also.