Apple has released the AirPods Pro 2D15 firmware update. Details of the changes made have not been revealed, but the update is believed to have fixed an alleged error in version 2C54, taken off the air shortly after its release, by reducing the quality of noise cancellation for bass sounds.
The measure caused the user base to be divided between this and the previous version, launched in November 2019 under number 2B588. Therefore, all users will be able to update their headphones directly to the AirPods Pro 2D15 firmware released today, regardless of which firmware is installed on the device.
Unfortunately, there is no way to force the update to arrive, or even to perform it manually, being necessary to wait. Remember that the headphones need to be connected to an iOS device and be in the case to receive the update. To check the version your Apple AirPods are in, simply access the Settings application, go to the About tab, and then select AirPods Pro.