iPhone 11 has issues with audio during video calls

When I am using iPhone 11 for video calls, my voice goes mute during the call on the other end infrequently. I can hear them properly, but people on the other end can’t hear me. This happens off and on through out the call infrequently.

I have contacted Apple support a zillion times, got 3 new iPhone 11 exchanged but in vain.

However, my iPhone 10 and my iPad works just fine without any issue. So this definitely can’t be my network issue.

Also, I have tried contacting different people to check if the issue could be at the receiver end. But the issue stays the same with everybody.

I have tried making the video calls using my wifi, my data plan, others wifi but the issue stays the same.

I have tried to restore my phone manually, did factory reset, restore my phone without my iCloud account and tested without any data on my phone to check if it’s some software issue. But no fix !

I have been struggling with this since last 8 months and hv been loosing time of my warranty. I need a solution !! Can somebody please help me!!!!