https://wccftech.com/airpods-2-firmware-updated-to-2d15-after-airpods-pro/

Apple has just updated the second-generation AirPods to the 2D15 firmware update. It's the same update that was earlier released for AirPods Pro.

AirPods firmware has been a small rollercoaster ride lately. Apple pushed 2D15 for AirPods Pro users that apparently fixes some lingering issues. Previously, the 2C54 firmware update was released for users which was immediately pulled because it apparently broke noise cancellation in favor of more bass. But Apple, apparently, made everything right again with the release of 2D15 for AirPods Pro.