Hi,
This issue seems related to Adaptive brightness settings. Adaptive brightness feature adjusts your screen brightness according to the light around you. To resolve your concern, we suggest that you disable the Adaptive brightness feature. Here’s how:
- Go to Control panel.
- Select Power Options, and then click Change plan settings.
- Select Change advanced power settings.
- Expand Display, and then expand Enable adaptive brightness.
- Change the settings to Off and click OK.
Kindly ensure also that your Surface Book is up-to-date to maximize the device performance.
Let us know if you need further assistance.