https://wccftech.com/microsoft-surface-pro-4-is-getting-new-firmware-update-1914-13-0-1063/

Microsoft has released new firmware updates for its Surface Pro 4, focusing on security and system stability. This latest update doesn't bring any new features, focusing only on system improvements, connection stability, and security fixes. May 2020 firmware update is available for Surface Pro 4 devices running Windows 10 October 2018 Update, version 1809, or later.

The above updates are released as a “Gradual Roll-out," which means they won't arrive for all the devices at the same time, but will eventually be offered automatically to all devices over the coming weeks. You can force download these latest Microsoft Surface Pro 4 firmware updates via Settings > Update & Security > Windows Update > Check for Updates. Do be aware that unlike optional software updates, you cannot uninstall firmware updates.