MOST HUR 997 KIT-210 No audio

Issue description
Hi,
unfortunately, I am not getting any sound after connecting MOST HUR and Kenwood DMC8019DABS.

The original PCM2.1 is operating properly.

I tried/checked already:
* Flashed two different images, flashing works fine (at least USB-Updates reports no errors and finishes, I can see green blinking light while USB is connected)
997 -> 05-08 -> New board - starting March 2011 -> 997 NEW KENWOOD -> Kwdv2_997-05.enc
997 -> 05-08 -> New board - starting March 2011 -> old -> 997 - 05-08 - Kenwood new

=> still no sound
=> don't any light when MOST HUR is connected in car, not sure this is correct
=> production date is 2012, so most likely correct with new board, or?

* Yellow is getting 12v from Ignition
* Black ground is fine
* RCA Front and Rear is properly connected to Radio
* CanBus Hi/Lo verified
* Cable-Connections are verified
* Radio is sending 12v on remote (connected to MOST HUR remote in)

The radio itself is working (could not power on via red MOST HUR, but when connected to 12V it is working)

My setup
Porsche 997 C4 mj. 2006 Cab
NAVTV MOST HUR 997 KIT-210 (got it as a gift, it is believed to work)
USBMOSTIR U:3 06/04/2008 S/N: 70086 P: 04/16/2012:1
USB-Updater shows: COM3 | MOST HU 997 02/28/2011 | 00070086
Kenwood DMX8019DABS

Original PCM2.1 with Phone, Navigation, no disc charger was working before

Wiring
NAVTV
12V Ignition/According -> Fuse Box C-6
Remote in -> Radio Power Control (blue/white No.1), delivers 12v
Foot Brake -> Not connected
Reverse -> Radio Purple/White Reverse Sensor
Illumination -> Radio Orange/White Dimmer
CAN Hi -> Car CANBUS Hi
Ground -> Car Ground (ISO in Radiobay)
IR -> Not connected
Parking Brake -> Radio Parking Sensor (light green)
VSS -> Not connected
12v ACC Out -> Was connected to Radio red, but did not deliver 12V, so not connected
CAN Lo -> Car CANBUS Lo

RCAs connected to Front/Rear of Radio
Directly connected to Fiber (no extension used)

Don't believe MOST HUR is defect as it is possible to be flashed.
What else can I check or verify?

Thank you very much.

Best,
Holger

The Kenwood has made its name for quite a long if you see their journey. I remember even in my childhood my parents used to buy products of it. Now my kids means the third generation and like to write my research paper for me online because it meets their needs accurately.