Hello Brian McKechnie,
Welcome to Apple Support Communities. These symptoms match those mentioned in the following section of About 4K, HDR, HDR10+, and Dolby Vision on your Apple TV 4K - Apple Support so we'd recommend starting there.
"Get the best picture
Apple TV 4K is designed to provide the best viewing experience based on the capabilities of your 4K TV. In some situations, you may experience issues or need to manually check your configuration. This could include:
- TV image is tinted, color is too bright, or has intermittent or no video.
- Intermittent static, snow, or sparkles on the screen.
- Unable to use HDR, or Dolby Vision on a supported TV.
- Audio issues, like audio drops, noise, or audio/video out of sync.
If you have any of these issues, make sure that your Apple TV has the latest version of tvOS. Then follow the steps below.
1 Make sure that your TV supports HDR10, HDR10+, or Dolby Vision
In order for Apple TV 4K to automatically set your display format to HDR10, HDR10+, or Dolby Vision, your TV must be able to display HDR10, HDR10+, or Dolby Vision at 60Hz (50Hz in Europe). Apple TV 4K can display these formats at 30Hz (25Hz in Europe), but you’ll need to enable Match Dynamic Range in Settings > Video and Audio > Match Content. If you aren’t sure which formats your TV supports, check the user manual for your TV.
2 Use the correct HDMI input and settings
Depending on your TV, you may need to use a different HDMI input on your TV for high quality 4K or HDR video. For example, some TVs only support HDR on HDMI input 2 or HDMI input 3. Check your TV user guide to identify which inputs support 4K and HDR.
In addition to using the correct HDMI input, you may need to enable HDR10, HDR10+, or Dolby Vision in the video or HDMI settings on your TV. In some cases, the setting may not refer directly to HDR10, HDR10+, or Dolby Vision. Examples include Ultra, Deep, or Enhanced video or color.
3 Check your HDMI cable
If there's an issue with your HDMI cable, you might see a message on your TV that says that your HDMI cable might be having trouble maintaining a stable connection. If your Apple TV 4K is connected to a 4K compatible TV, you can run a 2 minute test to check your HDMI cable connection. Go to Settings > Video and Audio and select Check HDMI Connection.
4K video, especially HDR10, HDR10+, and Dolby Vision, requires an HDMI cable compatible with these formats. Apple recommends HDMI cables that have the Compatible Dolby Vision mark as they have been tested with Apple TV 4K and a wide range of TVs. An example is the Belkin Ultra High Speed HDMI Cable.
If you still experience issues with your HDMI cable connection, check all of your connections and make sure that your HDMI cable has the label “Compatible Dolby Vision.”
4 Check other components
If you're using other components, like an audio video receiver, HDMI switch, or sound bar, temporarily connect your Apple TV 4K directly to your TV. If the issue doesn’t occur when directly connected to your TV, check the following:
Receiver or sound bar
If you're using an audio video receiver or sound bar, you should check its capabilities, connections, settings, as well as the following:
- Verify that your receiver is capable of displaying 4K and higher video, and that you're using HDMI inputs that support 4K and HDMI 2.1.
- Receivers that support HDR10, HDR10+, or Dolby Vision often require a firmware update to add this support.
- Check the video and HDMI settings on your receiver after updating, as you may need to enable enhanced HDMI in settings.
- Make sure that all the HDMI cables connecting your Apple TV 4K to your TV and receiver are compatible with 4K and HDR video."
All the best.
