Apple has released new firmware designed for the second-generation AirPods Pro, which should be arriving at Apple retail stores and to users tomorrow. There’s no release notes on what at the firmware entails.
Installation should automatic when the AirPods are in their charging case, the case is plugged into a charger, and the linked iPhone is in close proximity and connected to Wi-Fi. You can check the installed firmware revision in the “General” settings menu, by selecting “About,” then “AirPods.” Look at the number next to “Firmware Version.” The latest firmware upgrade should be 5A377.