Hi
Using the above
Using HDMI leads capable of passing full 4K
Using HDMI 1 input on soundbar
Using ARC output from soundbar to ARC input on TV

Plug in device capable of output up to 1080 into HDMI 1 Input on SB I get the volume setting onscreen on the TV.
Plug in 4K device into same NO volume onscreen setting on the TV. (Have tried several 4k devices.)

Anyone any ideas.

Thanks