Incoming call ringtone used buttom speaker only

Does any one noticed that when receiving incoming call the phone only rings from the bottom speakers causing lower ringtone volume than playing it on musicplayer, is that normal, and could the both speakers be enabled during incoming call

Edit:Sony Xperia z2 had same problem and it was solved in this thread http://ift.tt/2axmOAr , any hope for the Z5 :(

from xda-developers http://ift.tt/2ayp4dW
via IFTTT