My callers were saying the phones went straight to voicemail. Sometimes I would have a missed call, other times I did not. Sometimes it would ring once and then go to voicemail.
After 2 customer service rep calls with no resolution, my third call was resolved.
Have the rep check the number of rings that are set before going to voicemail. For some reason, mine was set at zero. So all of my calls were going straight to voicemail. I don't know how it was setup this way. I never initiated the request.
As soon as she changed it to 8, after a soft reset, my phone started working again.