Controlling Aria Player mixer from Reaper Mixer

[2mGamma]

Hey all !

Before posting, I did extensive research and that only brought me partially close to my goal so I'm here searching for light from thee, the experts

I set up Aria Player (GPO4) as only 1 instance. I used the "create 16 child tracks" option and imported midi items into each track. When I play back every thing sounds as it should but when I try to do some mixing (adjust volume and pan for each instrument), I can only do it from the Aria Player mixer. The Reaper mixer does not seem to have any effect over the Aria Player instruments.

I found a couple posts with a similar problem. As mentioned, I read them throughly but I just could not get the problem corrected. My apologies if I am asking something that has already been solved before.

Thanks in advance !