Person on the other end has dead air too.
In some cases, if I stay on the line for 30+ seconds, I can finally hear the other caller and they can hear me.
I've logged a call with VFNZ, but they say it's unheard of (no pun intended).
Multiple locations throughout Auckland. A complete reset of the phone (including a software restore with no backup restore) didn't change the behaviour, but it went away for a bit then started happening again this morning.