Sound Quality and Lag when using WebRTC with Unity on LG Phones

We are using WebRTC to make a voice call between an Android Unity Application and a Web Application (not Unity). When making the voice call on an LG phone, the audio going from the phone to the Web Page has large (10 second) and worsening lag and poor voice quality (crackly and slow). Voice coming from the Web App to the phone is fine.

The issue does NOT present itself on other non-LG phones. The issue does NOT present itself outside of Unity. (Using the WebRTC code by itself).

Does anyone have any insight into why this could be happening?