Neo U1 Won't play AAC 5.1

Are you running Amazing Prime as the app itself or are you using some Amazon Prime plugin in Kodi?

SPDIF can carry:
2 channels PCM (uncompressed)
5.1 compressed signal (AC3, E_AC3 and DTS)

Amazon Prime is currently offering AC3 or E_AC3 depending on the source so you should get what you want using SPDIF if the Amazon App you're using offers it
Hi! I'm using the app from Google App Store, and I'm not getting ac3 or DTS.

Is anybody getting ac3 or DTS using Amazon prime video?
So just to understand, if you play a video that has 5.1 audio track, you will still have sound but only stereo? Or you will only have stereo when you play a video which has stereo and no sound at all for a 5.1 video?