[CO17Forester]

The aftermarket camera I installed in my 2017 had lines that could be turned on or off, my head-unit adds the lines to the video. When I first installed the camera I had both sets of lines and it sort of looked like your 2016 photo until I turned the camera lines off.

With your headunits being the same I would check settings and maybe software versions.

 

[CO17Forester]

Looking at the Subaru parts page, the backup camera in a 2017, only fits a 2017 or a 2018. The 2014-2016 models use a different camera.
You may need to switch to a 2017 camera. At $250 from Subaru I would be going to the Pick-n-Pull looking for a camera.

2017-2018 Subaru Forester Camera 86267SG500 | Subaru Online Parts

 

[CO17Forester]

@RKImpzFrst15 On my 2017 the head-unit adds the lines to the video from the camera, since I used an aftermarket camera it had the option to have the camera supply the lines if needed. Turning off the lines from the camera fixed the double lines, it was not a ground problem in this case.