Audio management 1 of 2: volume
In a video call, audio was extremely quiet, too quiet to hear comfortably. I turned up the phone's audio as much as possible, and it did make a difference, but even at the phone's maximum volume it was too low.
My phone is an LG V20 running Android 7.0. The other party was using an iPhone; I don't know details but could find them out if needed.