2015 silverado 2500 aux input for radio acting as an output

[David Hh]

Installed a aftermarket radio in my 2015 Silverado 2500. It plugs in to all the factory harnesses with no splicing or anything.  Now I have an issue where my aux port in my center console is acting as an output instead of an input. I can hook headphones to it and listen to the music instead of it allowing music to be played through it.

[David Hh]

Anyone else have any issues like this where it fed audio through the aux port?