17 beta 6 on FireTV 2nd Gen – audio issues

I’ve read the sticky about API 22, but I don’t think this is related.

Hardware:
FireTV2

TV: Sony BRAVIA KDL46HX800
Dolby: Dolby Digital

LG soundbar NB3740 (Spec sheet here http://www.lg.com/us/support/products/do…0Sheet.pdf)
AUDIO FORMATS listed as supported for the sound bar
LPCM •
Dolby® Digital •
Dolby® Digital Plus •
DTS® 2.0 •
FLAC (Up to 192kHz) •
MP3 •
WMA •
MPEG2 AAC

Setup: FireTV2 HDMI > TV
LG soundbar NB3740 SPDIF > TV

Several of my sons videos I’ve AAC encoded using default settings in Handbrake, but when I play in Kodi either the audio is silent for two or three seconds then turns on, or it never does. To get the audio back, I must rotate through the input sources on the soundbar to get back to HDMI for the audio to work. This didn’t happen on 16.1

I chose to “reset audio back to default” and thought it worked, but it started again just an hour or so later.

Someone mind helping me find the proper settings for my setup?