VoIP phone not working with R8000 Router

Hello!  I purchased a R8000 router for my home network a few weeks ago.  I have been using a $60 Belkin router for last couple years and thought an upgrade was in order especially since this year my wife has been working from home.  She does lots of video conference and her employer (based out of state) provided a VoIP phone that is part of their network.  (It is a Polycom VX400 Phone) So, it’s just like she is sitting her office there.  (just dial extension numbers, boom, has her boss, etc,)  Works very well.  A better router seemed in order though.

Well, long story short is I cannot get the phone to work with the R8000 router!  The Belkin was just plug and play.  Just worked.

I have been on the phone with Netgear support, but no joy.

I have tried DMZ

I have tried Port forwarding

No joy at all.

Here are some symptoms.  First, it partially works.  That is, you can make calls to people, but just not people on the same VoIP service, AKA the people in her office.  In that case, calls goes through, but no audio, either direction.

Another thing noticed.  If she forwards her VoiP phone, which she does when she travels, the screen on the phone shows the number it is forwarded to.  BUT when it is connected to the Netgear router, and things are not working, the forwarded number does not show on the display, though the phone is indeed forwarded. Don’t know what that means.

I’m pretty much at my wits end.  I have gone back to the old $60 Belkin router, and occasionally fool around with ideas with the Netgear R8000. But mostly, I feel like I spent $250 and don’t know where to turn.

Thanks!  -Carl