Last month, Apple introduced a new version of Firmware for AirPods, but after the update, some users have reported that the noise reduction function of AirPods Pro has become worse after it has been upgraded from 2B588 to 2C54.
Perhaps because of this, Apple has also quietly suspended the 2C54 Firmware update of AirPods Pro, so some AirPods Pro users have not yet obtained 2C54 Firmware.
The website RTINGS re-tested the AirPods Pro after updating Firmware. It was found that the noise reduction function of the AirPods Pro was significantly worsened after the upgrade, such as being unable to block the engine sound of airplanes or buses, but it was possible to do so before upgrading Firmware. However, after the upgrade, it is not a downside. For example, bass accuracy is better than before.
Check Firmware Version
You can see the firmware version in iPhone “Settings” → “General” → “About this device” → “(Your name) AirPods / AirPods Pro”.