Data Network error

Hi, i have a LG g3 Beat D722, and updated it into lollipop 5.0.1, but now the Data network connection does not work permanently, i have to turn on and off the airplane mode and then the data network connection icon appears in the notifications bar, till the phone block the screen...when unlock de phone the connection is lost...so i need turn on and off the airplane mode again.
pls help!!!

thnx.

PD sorry for my english...