Apple today released new firmware updates for the Beats Fit Pro and Powerbeats Pro. The Beats Fit Pro and Powerbeats Pro now feature firmware version 5B66, up from the prior 5B55 firmware that came out in November 2022.
Apple does not offer information on what's included in refreshed firmware updates for the Beats Fit Pro and Powerbeats Pro, so we don't know what improvements or bug fixes the firmware brings.
There's no standard way to upgrade the Beats software, but firmware is generally installed over-the-air while the earbuds are connected to an iOS device. Putting the Beats in the case, connecting them to a power source, and then pairing them to an iPhone or an iPad should force the update after a short period of time.
If we find notable changes after the firmware update is installed, we'll share details, but the software likely includes performance improvements and bug fixes rather than outward-facing changes.
Source: Macrumors