https://wccftech.com/fresh-microsoft-surface-firmware-updates-are-now-available-for-various-devices/

Microsoft has released firmware updates for a number of its devices, including Surface Pro 4, Laptop 3 (with Intel processor), and the original Surface Book. These updates focus on performance improvements, along with addressing some critical security vulnerabilities.

For Surface Laptop 4, the latest update was released on July 29, now available for Surface Pro 4th Gen devices running Windows 10 May 2019 Update, version 1903 (19H1), or greater.