After upgrade to Kodi17 AC3 stereo doesnt play

I have Kodi installed on my Nvidia Shield and now it wont play AC3 stereo (2 channel) videos.

I had 16.1 installed but overnight Kodi 17 was installed (I didnt realize I had automatically install updates checked) and now stereo Dolby doent play on videos. I get a brief message but havent been quick enough to get a pic or even read it. Ive got a high end sound processor and amp but they do me no good for Dolby stereo now. Whats that all about?