Anyone replace their head unit and use a pac RadioPRO or Metra harness to retain jbl?

2012 iv with nav and jbl. I had the alpine ilx 207 installed and used the pac RadioPRO 4 to integrate the jbl and steering. The installer said he ran into an issue where the right front door speaker wasn’t working and when they called pac they told him to plug into the “non amplified” port on the pac and turn the gain up. They got it working but I can hear hiss/static at low volumes when the car engine is not running. I asked the installer if a different harness would fix this and he said the Metra would not have the hiss.

Anyone have experience with either of these and chime in if the hiss is normal?