Why my AirPods model A2931 won’t update to the latest firmware?
I attempted to apply the most recent firmware update to my second-generation AirPods Pro, but unfortunately, the update was unsuccessful despite following the provided instructions.
Did you put the AirPods inside the case, open the case again to let them connect to your iPhone, leave the case open and the AirPods inside and connect the charging cable to the case?
Then wait a couple of minutes for the new firmware to download.