Why does my LG V30 has an echo during calls?

[Android Central Question]

On my LG V30 phone, when talking to someone, the other end hears their voice back. I have tried voice cancellation on and off but it happens in either case. Also tried using it without a case but it doesn't help.
What should be causing this issue and how can I fix it?

 

[No1ButMe]

Could possibly be a network issue or more simply the volume level it to high .