Unable to switch audio with App/RPC

Hi,

i figured out a weird bug that is in OSMC on the Vero devices for a while …
I am sometimes using an App to Navigate Kodi with my iPhone.

Everything is fine, except I am unable to switch audio or subtitles. It works fine on my MacMini. Its the same when I try to use the JsonRPC, it does not return an error.

This is not limited to the Vero V, but also to the 4k+ model.
I can switch the audio with the gui