Transparency mode not working on my AirPods Pro when I add the second one to my ear.

I actually want to inform what I did to fix this as the previous answers to this question did not work for me.

I did the reset for which you can find instructions on the web, and while I'm not sure this was necessary, it was my first step. I then found that instead of using the top right drop down on my iPhone to get to the Airpods app, I went into Settings/Bluetooth/Info and selected Transparency mode there and it started working again in both ears. Hope this helps someone!