[Kodi 17 Krypton] Android Box H96Pro Plus : DTS not working

hi everyone,

i recently bought an Android box, model H96 Pro + which have Kodi 17 installed.
this box is connected to my amp. Yamaha HTR-3065 via HDMI (no optical for the moment).
this amp is then connected to my Panasonic Viera TV via HDMI too.

I have done Kodi configuration the same as it is on my ATV2 (Kodi 15) in system/audio menu :

with my old ATV2 Dolby Digital (AC3) and DTS worked fine
witch this new box only DD works.
when i play a DTS file, i have no sound from my amp.
if i uncheck DTS capable, i have PCM sound from my amp.

im I doing it wrong ?