One of the best features of Google Home Hub is Ambient EQ. But if you find that Google Home Hub is not obscuring your screen in dark rooms, the function can be disabled in the Hub itself in a hidden menu.
Ambient EQ is an excellent function that adjusts the brightness and color temperature on the screen. Screen to match the surrounding light in the room. When the screen saver goes away, the color adjustment makes the photos appear printed instead of on a screen. And when the lights are turned off or off, the screen should dim automatically to prevent it from acting as a bright flashlight in the room. This makes it the perfect device for your living room or bedroom.
All that is true unless Ambient EQ does not work, as shown in the photo above. The Google Home Hub above was not dimmed at all after the initial configuration. And a factory reset did not solve the problem. The environmental EQ settings were not deactivated in the Google Home application. It turned out that Google Home Hub has a hidden screen settings menu. And from here you can disable Ambient EQ, which overrides any configuration you have in the application.
So, if your Google Home Hub is not dimmed, the first thing to do is to slide up from the bottom of the screen. 
On the far left, tap the sun icon to show the brightness setting.
On the far left, tap the sun icon again.
 You should now see an A in the sun icon and the words "Environmental EQ" should appear.
Henceforth, the attenuation should work correctly. This is a fairly simple problem to solve, made more difficult only by the fact that the configuration involved is not intuitive. If you set the brightness in this menu in any setting of 1-10, the environmental equalization is disabled.
Source howtogeek com