VoIP Calling Unavailable after iOS 10 Update

What is the app version of the RingCentral Mobile app you have installed on the iPhone?

Thanks for the info Eli.

I looked over the app with one of my Colleagues who is running iOS 10 on his iPhone and version 8.2.2 of the app. He actually used to be an Apple Genius too so he really known what he is talking about when it comes to the iOS issues.

We tested VoiP calling over his cellular carrier network and had no issues, so I want to verify a few settings with you. When you open up your setting on the Moble app can you make sure that the VoiP calling option is turned on and showing a nice Blue indicator showing it is on. After that open the Call Settings options and make sure that you have the Always Use VoiP setting selected from the list of options there.

If both those are set correctly you will need to make sure that you have a good solid Data connection from T-Mobile. A VoiP call is going to use your Data connection, not your calling signal if that makes sense. You may have good call reception, but a really bad Data connection. In this case, the phone would not be able to make a VoiP call from the app.

Thanks, Let me know if this helps.

Thanks everyone for the insight, I can verify that all of my settings are correct.  After reviewing Brandon's post, I believe this is a network issue.  The odd piece is that when I test my data signal through SpeedTest.net, I appear to have a great data signal/speed.  Hopefully the developers will uncover what is going on, unfortunately I made the mistake of updating to iOS 10 to early.  

Hi all, early this morning Apple pushed a carrier settings update that has fixed the issue.  If anyone is having this same issue, sync your phone to your itunes account and click the check for update button.  This should automatically download the new carrier settings correcting the issue.  Thanks again to all that have contributed to this thread, I really appreciate the support.

Same error on my Pixel 3xl (Google Fi).  RC Phone app works perfect while on wifi, however once changed over to mobile data I instantly see an error that 'VOIP calling is unavailable".  Outbound calls to all numbers fail.  Inbound calls from anywhere are successful.  I currently have the app set to use RINGOUT because thats the only way I can complete an outbound call without wifi.
Help?