Need help fixing AUX with no sound

[ILoveMyBenz69]

Hi,

First I have ML350 2015 with NTG 4.7
I bought an Android Unit N600 Snapdragon 625 9 Inch, everything work perfectly, original NTG, 4G, GPS, Carplay.... Except for the sound.
I never used my AUX before since the 4 years I have my truck and just realized it simply doesn't work, even when I plugin an MP3 player, Ipad or Ipod, everything else have sound, radio, Bluetooth, CD..... I even tried with another AMI to AUX adapter

So far a list of everything I tried:
Removed the Ground loop noise isolator I bought to connect directly to the AUX AMI adapter
https://www.amazon.ca/gp/product/B019393MV2/ref=ppx_yo_dt_b_asin_title_o05_s00?ie=UTF8&psc=1
Because at first I thought it was my new head unit that didn't had sound coming out to AUX, I plugged in a pair headphone in the cable running in my center console using the Ground loop noise isolator.
Tried another AUX to AMI cable, I also tried the USB to AMI and plugin my phone and I can see it's charging
Resetting command by oldling the power button for a few second.
Removing fuse 100 and 147 for a few second in the fuse box under the rear left seat
Removing fuse 21 for a few second on the side passenger door fuse box.
Tried multiple devices in the AUX that I know have sound
I even removed the Android unit and put back everything to it's original state, just to make sure the Android unit is not in fault.

I took a couple of pics to show my setting and hopefully someone can help.

My AUX is available and selected

In engineering menu
7.5 - Most is ON and Audio source is External amp
7.7 - Audio AUX is ON

The AMI I use and I even tried a second one.

Here's the before and after for those interested on the Android unit, ( My problem had nothing to do with the unit, my AUX doesn't work no matter what device I use)

 

[JaViSiMo]

Mismo problema y sin solucion

 

[richard]

You dont have UCI turned on (set to Not Installed), I,e you've turned off the UCI so AUX via UCI can't work. When UCI is not configured, AUX is via the analogue AUX connections on the back.
Turn the UCI back on and use the Media Interface -> AUX lead you have bought. (AMI is an Audi thing, not a Mercedes thing, in the case of Audi actually very similar, but not so true with other cars with the same connector)

R