mp6365

I am having issue with some Speco smoke detector covert cameras. Currently, I have 6 installed and am having problems with only 3. What is happening is that on the display I am experiencing the color changing between red and green spuraticaly. Tried replacing the camera with another of the same make and model with no success. If I replace the camera with a different type (dome) the picture comes up fine. When I bench test these cameras they work fine. Anyone ever experience an issue like this?