Dirty power (rear camera issue)

I have Prius Gen 3 2010 Five. When I purchased it in 2014 I removed navi head unit and replaced it with Pioneer AVIC-8000NEX + rear view camera (Clarion CC510). Everything worked fine for 2.5 years. After that I started noticing artifacts on the rear camera. They might be a small colored "snow", later turning into white "snow-storm" making that camera useless. If you're lucky and put your car on a reverse fast, you can have a chance to see a clear picture for a few seconds. At the end of your trip camera is always unusable.

At first I thought "ok, faulty camera". So I bought a new one on Amazon, exact same model. Spend few hours to change it. And issues still there.

My next thought was - oh my God, I have to spend another $1K to buy a new Carplay head unit to replace that Pioneer. Today I realized that my Pioneer was just fine. Took old camera and connected it to my TV and to the 12V power supply - perfect picture on my TV. Next, I connected Pacman game which have video out like my rear camera to my Pioneer in the car - and image was perfectly clear. Next, I connect my old camera with an external power supply to the Pioneer and again picture was clear. It's only when I connect camera which have 12V from the car - then image is crappy starting from 30seconds.

At this point I'm convinced that something happened with power system of my Prius and my rear camera now have dirty DC input.

Two questions:

1) How to fix that? Currently rear camera's DC input is connected to the power line of the Pioneer's head unit.
2) Is there any risk that my Prius electrical system is experiencing an issue which I may overlook? Don't want to spend $$$$$ to fix it later when something arise.

I would appreciate any advice.

 

My camera is NOT powered from reverse lights. Power source is the same as for main head unit.