Improvements and fixes in the updates
June 2023 updates
June 23 release
The following update is available for Surface Pro 6 devices running Windows 10 May 2020 Update, Version 20H1, or greater.
This update:
- Resolves external display issue.
- Addresses potential security vulnerability.
Windows Update Name Device manager Surface - Firmware - 239.645.768.0 Surface UEFI – Firmware Surface - Extension - 6.13.137.0 Surface Dock 2 Firmware Update - Extension
Source:
Surface Pro 6 update history - Microsoft Support
Learn about all the latest updates to your Surface Pro 6.

Manual download:
Download Surface Pro 6 Drivers and Firmware from Official Microsoft Download Center
This device has reached the End of Servicing. The following packages are no longer being updated with newer drivers and firmware.
www.microsoft.com