SUBARU Harman Kardon no sound on rear speakers
SUBARU Outback 2016 Harman Kardon no sound on rear speakers.

I have installed joying 11.6" head unit with can bus decoder to my 2016 Outback with Harman Kardon audio system.
The front door speakers sound ok (the quality you could expect from this shitty product).
The rear speakers and subwoofer has no sound.

I have tried all menu options on the stock android (amp power, many canbus type settings, equalizer settings).
The android system has latest updates.
Joying Customer support does not help me with this shitty product.
They already agreed that the wiring harness they sold is badly wired, but has no solutions for my problem.
I have provided all the schematics of the car, all connector photos, videos with my problems, but I believe guys who work with this system are not qualified enough to help me.
I have even uploaded many videos to youtube to search for a help. (

Latest offer from Joying customer support is to install my head unit to another car?!?!? WTF?!?!?!

Maybe anyone has a solution for my problem?

P.S. I do not recommend anyone buy the joying products.