Samsung TV only displays HDR10+ when input signal plus is turned off

[bkwashby]

Hello

I have a Samsung QN65Q900R 8K TV and whenever I input an HDR10+ signal, it only displays a standard HDR10 picture. But when I turn off the Input Signal Plus, the TV displays an HDR10+ picture.

Why doesn't HDR 10+ work with Input Signal Plus turned on?

Is there a chroma limitation or bit depth limitation? 

[Helenna]

Hi, just to confirm are you facing this issue while trying to connect external source?

Have you tried changing HDMI cable and check?

[bkwashby]

It's not the cable. The TV won't switch to HDR10+ if the input is 12bit and the chroma is set to 4:4:4. It will only work on 12bit if the chroma is 4:2:2 or 4:2:0. Works every time if the input is 10bit. Wish the e-manual was more detailed to reveal these specs.