Using the balance control merely reduces the volume of the AirPod side that is louder. It does not fix the problem with the screen or port of the inner canal clogged with dry earwax. I have used Q-tips soaked in alcohol, and this worked the first time, clearing visible earwax over the screen. Be sure to have the port dependent, facing downward so the alcohol and wax do not get into the AirPod behind the screen. If we had a diagram of what the plumbing is this would be most helpful to understand what’s going on. Subsequently, months later I got the one side louder issue and this did not work, as there was no visible earwax this time. Somewhere inside the tiny canals get clogged and prevent the free flow of air. Please view the solutions of what to do with the two orifices to clear the ports of a bass reflex design being interrupted by wax, and must be cleared. There’s no access to do this directly. Good luck, and be careful. Adjusting the balance will not fix the issue but reduce the quality of sound by reducing the volume of the side that is functioning more normally.