There's actually al lot of topics about this issue, in kodi forums and android powered tv box forums. There's nothing wrong with your setup. it's just the change Kodi made with the latest update to 17 Krypton, they update there software to the latest audio standards and only one standard. In previous versions it was compatible with more standards so but this was to complicated for developers. Unfortunately the audia passthrough like DTS-HD, Thue HD and Atmos are no longer working with a lot of android tv boxes like Himedia now. We have to wait on a FW update to fix this issue, i hope they will fix this soon. Until then you have to use Wrapper in order to use high quality audio streams.