I have a new KD-65XF9005 and am struggling to get proper quality on 4K HDR and Dolby Vision from my Apple TV 4K in Netflix.

If I set my Apple TV at 4K SDR, the picture looks great in the Apple TV Netflix app, but if I change it to 4K HDR or Dolby Vision, the picture looks very dim. The Apple TV menu and Netflix menu are OK, but the content itself is dark and "washed out".

I've tried both with and without Enhanced mode on the HDMI input settings. Actually the Apple TV detects when I set it to Enhanced mode,  and asks if I want to enable Dolby Vision.