Problem with Center Channel on 5.1 Live TV Content

I've recently bought a new TV and now I've got some problems with the audio during Live TV.
My Setup now looks like this: HTPC(Kodi) -> HDMI: Audio/Video -> TV -> HDMI ARC: Audio -> AVR.
The problem now is that if I watch anything live with 5.1 Audio the center channel audio stream is missing, !!!!BUT!!!! if I record such a program and watch the recording 5.1 audio works fine as expected.
Other Audio format on video files also work as expected

I've tested this with the latest stable libreelec 8 as well as the current libreelec 9 alpha.

Maybe someone has an Idea??

Thank you in advance!!