The link you posted was "
http://www.needrom.com/category/lenovo/serial-k/k920/" and this has all rom & updates for K920, be it kitkat or lollipop. Please advise which file you have flashed.
Sent from my Lenovo K920 using XDA Free mobile app
Ok... Check this one - "http://www.needrom.com/download/lenovo-k920/"
"http://www.needrom.com/wp-content/uploads/2015/04/K920_ROW_S143_1502111114.rar"
This is the one .. S143 ROW.