Why does Night Light keep turning itself off after a few minutes?

Why does the Night Light feature on my Windows 11 PC turn itself off a few minutes after I enable it, even though the schedule is set correctly? Why does it sometimes stay on for hours and other times switch off almost immediately?

Could this be related to a graphics driver, a power setting, or a conflict with HDR being enabled? And is there a fix that keeps Night Light on without manually toggling it every time?