Ok

When Oppo / Firestick play a HDR10 film through UHD722 the LG shows HDR10 on screen and when I check the picture format selected by the TV it shows HDR10.

When Oppo / Firestick play a Dolby Vision film through UHD722 the LG shows Dolby Vision on screen and when I check the picture format selected by the TV it shows Dolby Vision.
Similarly Sky shows either a HLG or HDR10 picture as detected by the LG TV

Signal path is Oppo (or Firestick) > UHD722 input > UHD722 output to LG HDMI input. Sound is HDMI to UHD722 and then Meridian MMHR to 861v8.

Not sure if HDR10+ works from Oppo to UHD722 as I've only just realised I have 2 discs with this format and I've probably not watched them since buying the LG TV.

Hope we're on the same page now.

Regards
Bob

861v8, UHD722v2, 5200s, 5200HCSEup, M6s, 3200s, DSW, Sony 55A95L, Oppo 203, Sky Q Silver
Samsung QE43Q65B, Oppo 105 & Sky Q Mini