HDMI-CEC Volume OSD

Hey, I’ve got my odroid happily controlling my amp and tv via CEC but I have a weird issue that may or may not be solvable.

My amp is a Sony STR-DN1080 and normally when you adjust the volume you get an OSD showing the current level. If I change the volume via coreelec then it changes on the amp successfully, as shown on the front panel on the amp itself but what I seem to lose is the OSD as well. This is annoying is it means I have no idea what the volume is without then looking at the amp.

Is this an issue with the amp do you think? Maybe the amp only displays onscreen if you use the included remote?

I think that some amps can only display OSD when the output resolution is 1080P or lower (or something like that)
If you run your GUI at a higher resolution, that could be your problem.

Thanks. I’m running at 1080p.

When you have connected all with CEC you normally use the TV remote to control the volume not on CoreELEC.
I have the same, LG TV, AVR by HDMI ARC on TV and N2 on TV.
I only use the TV remote.
That’s the purpose of CEC, only one remote (TV remote) for all.
The TV is always the"master" on CEC.

I use my MCE remote to control coreelec. This works fine in turning on the TV/Amp/Odroid and vice versa to turn them all off. Also works doing the volume etc but I just lose the onscreen OSD for the volume control. It looks like this may be a limitation of either my amp or the HDMI-CEC spec in general.