Can't hear other party over calls.

[VINEET21]

I am having 2 lines activated on my iphone XS. Xfinity Mobile(XM) is my primary line while Verizon is secondary line that i'm using through esim. Both lines activated since more than a year and so far not issue w.r.t calls. From past 2 days, i can't hear other person while call connected through XM. Similarly, other person can't hear me while call connected. This is continue happening for all calls irrespective to any specific service provider. However, i am keep receiving SMS and data services through XM. Also, when i do whatsapp or facetime calls, i can hear other person which rule out issue with my phone. I did my phone reset(Erase all content and settings) but problem still exist.

[wpaulo]

Go to settings, cellular., cellular data options. On voice and data turn off VolTE. Also try connecting to a cell tower a few miles from your current location.

[DaveO3]

This is a long shot, but technically you cannot have two active CDMA lines on a phone, unless in this case you set up the Verizon eSIM as CDMA-less, which means it will not use old 3G or 4G CDMA. Check your settings to see if there is an option to do this, otherwise go into your Verizon account and look there, otherwise call Verizon. This means that your Verizon Settings need to have VoLTE on?

[VINEET21]

@DaveO3 I have being using both lines since november 2019 and not faced such issue so far. This is suddently stop working. XM support not able to identify the issue and ask me to check with Apple support. So, i booked the appointment with them and hoping they could resolve the issue.   

[VINEET21]

@wpaulo This is definately not the signal issue as my wife also using XM line and signal strenth is very good here. I tried changing cellular data from LTE to 3G but issue still exist.

[DaveO3]

I suggest that you run a few tests to see where the problem may be. For these tests turn off your Verizon eSIM to make sure that it isn't somehow causing a problem

1.) Toggle off WiFi Calling. If you still have a problem it may be one or more of your phones cellular radios/antennas are going bad, or you are connecting to a problem cellular antenna. 

2.) Toggle on Airplane Mode, toggle on WiFi Calling. This should be using WiFi radios/antennas to get to the XM servers. These would be the same ones that get you to WhatsApp or Facetime over WiFi which you say work fine. 

Based on the results you might get closer to isolating the problem.