Thumbs down [4.4.4] network sensibility decreasing

Hello,

Since the latest update in july, the phone seems to be in 2G 10/15% less sensitive as before and in 3G it is near 25% !!!

i use g-nettrack application to known cellID and sensibility values.

i choosed motorola because the xt311 fire is very sensitive and the moto e was before this update on the same way..

how to rollback the update ?