According to the Kodi community, audio passthrough is broken completely in Sony Nougat firmware. Nougat introduces the new IEC API for audio passthrough which Kodi uses. Neither Dolby AC3 nor DTS works on Sony. So MediaTek again failed to properly implement the new API.

Some apps use the older raw API for passthrough. DTS raw API, which has been introduced by Google in Marshmallow, is also still broken with the MediaTek driver that ships with new Nougat firmware.

Only the Video player can do proper passthrough for all formats as it has access to some private APIs.

This is a total shame!!! When you think it can't get any worse... Keep in mind that Dolby and DTS have been a standard for 2 decades and Sony/MediaTek still can't properly handle those formats.