There's a "fix" not sure if any one else found it but the blue tooth can be installed to the original harness and the stereo will fit. I ended up separating the Bluetooth receiver from the aftermarket harness and splicing into ground and power from the original harness,plugged in the connector to the aux side and it worked
Mine was doing the same thing, it would show aux for a split second but never stay on aux. I ended up just getting a cheap Boss head unit with Bluetooth and android auto/apple car play
