5.1 Passthrough issue with new Fire OS update

Hi,
I have started having issues with my 5.1 audio encoded files since my Fire TV 2 updated the software to 5.2.4.0 (565189620). Everything was working fine until this update (passthrough) but now I get only a static.

Here is my setup (the one that was working until the update of Fire OS):

Kodi 16.1 Jarvis
Audio output: 5.1
Enable passthrough
DD (AC3) capable receiver
DTS capable receiver

AFTV2 connected to my receiver (Poineer VSX 823) via HDMI

AFTV audio setting DD over HDMI Automatic

Note: 5.1 on Netflix works after the update, so I am assuming it should be a Kodi specific setting?

I greatly appreciate any help!

Thanks.