i updated my LG g2 to the 4.4 kitkat last week.

now i am unable to use youtube. no internet connection via the wifi for certain apps like youtube, gmail and GV.
i can use it if i go on data. tried same wifi via different android phone not on kitkat 4.4 though.
is there a fix to this?
Can someone help?
How can i roll back this kitkat update?

thanks