A work around:
Please check and confirm if you tried these same steps to update the firmware of these AirPods.
1 Make sure that AirPods are within Bluetooth range of their companion iOS, iPadOS, or macOS device.
2 Kindly listen to music or other audio content with the AirPods for at least 30 seconds.
3 Put the AirPods back in the Charging Case and close the lid.
4 Use the Lightning cable to connect the Charging Case to power. Wait 30 minutes. Then ask the customer to reconnect the AirPods to the iOS, iPadOS, or macOS device that they are paired to.
The lid of the AirPods Charging Case needs to be closed during the entire process. If it's opened at any time, the update is interrupted and it starts over