Volume Control on Apple TV 4K + Sonos Beam + LG C9

I have Apple TV 4K 2nd gen + Sonos Beam 2nd gen + LG C9. All are connected with eArc.

Until recently I was able to control the volume of Sonos with an Apple TV remote AND see the volume control indicator on the TV. Even though it was not showing the level it was behaving the same as if I use TV remote. This limited indication was ok for me. Now I don't see the indication at all. The volume still changes on Sonos, but there is no indication on TV. If I use the TV remote - it shows the control on the screen. Doesn't show with Apple TV remote.

Has anyone found a solution to why this happens?