Open Settings → System → Display → Night light. Turn it on manually and increase Strength long enough to see whether the screen gets warmer. If manual control works, check the schedule. If it is grayed out or only one screen changes, check the driver and how that screen is connected.
01The tint works manually but misses the scheduled time
Section linkOn the Night light page, turn on Schedule night light. Choose Set hours and test a period that includes the current time. If that works, review the schedule you had before, including whether it used Sunset to sunrise. Return Strength to a comfortable setting after the test.
02The Night light switch is grayed out
Section linkRight-click Start, open Device Manager, and expand Display adapters. Microsoft Basic Display Adapter indicates that Windows is using a generic driver for that adapter. Check Windows Update first. If it offers no suitable driver, check the PC or graphics hardware manufacturer for one for your model. Test Night light again after installing the applicable driver and restarting if prompted.
03The laptop screen changes but the docked monitor stays cool
Section linkIf your monitor and PC have compatible video ports, connect the monitor directly for a comparison. Keep the same Night light setting. If the direct connection works, identify the dock model and check whether it uses DisplayLink. Microsoft lists DisplayLink among configurations where Night light can be unavailable. DisplayLink documents support for some chipsets and outputs, so confirm support for your exact dock and port before changing its software or settings.