Sony AndroidTV KD-55XD8005 no DolbyDigital AC3 output

Hello,
i got a Sony Android TV and i installed the Kodi app from play store. My AVR is connected via optical out (S/PDIF) with the TV. When i play movies with DTS, the passthrough is working and my AVR can decode the audio signal. But when i play movies with DD AC3, i have no audio output. I tried all available options. My AVR shows: DolbyDigital2/0 and i can hear nothing.
The tv is running android 6.0.1, and official release of Kodi 16.1 “Jarvis”

When i play Netflix movies with DD AC3, the audio output works OK, also when i use the Sony own videoplayer app for the same video files, DTS and DD AC3 works fine.

Can somebody give me some hints? Should i create i log-file?