Dirty flashing? I don't know why you're having this issue but I have had issues in some roms where the aosp dialer come up blank with no digits.
What I did was search for blacked out dialer apks. Grabbed one for aosp and one for TW. Each time I go to a new rom I just overwrite the dialer apk, change permission reboot and good to go. Maybe that could be of some help maybe not. Just an idea and good luck
Sent from my SPH-L720 using xda app-developers app