AppleTV 4k (3rd) Flicker in Dark

I had this flickering issue with my Apple TV and it turned out that the HDR setting was messing things up. I found the fix in this article: https://pointerclicker.com/apple-tv-keeps-flickering/

Definitely give it a read if you're dealing with the same thing. Helped me out a lot, hopefully it does the trick for you too!

Hello Alaber90,

We'd like to provide you with a few steps that can assist you with correcting the behavior that your Apple TV is displaying:

"Restart Apple TV

Do any of the following:

• Press and hold both the Back  (Siri Remote 2nd generation or later) or (Siri Remote 1st generation) and TV   buttons on the Siri Remote until the Apple TVstatus light blinks rapidly.
• Disconnect Apple TV from the power outlet, wait five seconds, then reconnect it.
• Open Settings  on Apple TV, go to System and select Restart."

"Reset Apple TV

If you’re having problems and Apple TV still doesn’t respond after restarting, try resetting Apple TV to its factory settings. When you reset Apple TV, all data is erased, including your accounts and configuration.

You can also reset your Apple TV and update its software at the same time.

1. Open Settings  on Apple TV. 
2. Go to System > Reset, then select Reset. 
3. Resetting Apple TV and restoring it to factory settings can take some time, so be patient. If Apple TV still doesn’t respond, do one of the following:

• If you have an Apple TV 4K: Contact Apple TV Support.
• If you have an Apple TV HD and a Mac with macOS Catalina or later: Disconnect the power and HDMI cables from Apple TV. Connect one end of a USB-C cable (sold separately) to Apple TV and the other end to your computer. Open the Finder on your computer, select Apple TV in the sidebar, then select Restore. If that doesn’t work, contact Apple TV Support.
• If you have an Apple TV HD and a PC with iTunes or a Mac with macOS Mojave or earlier: Disconnect the power and HDMI cables from Apple TV. Connect one end of a USB-C cable (sold separately) to Apple TV and the other end to your computer. Open iTunes on your computer, select Apple TV in the Source list, then select Restore."

We hope this helps.

Have a wonderful day!