Third-party rearview camera
 

Hello everyone, I am a happy owner of a MAZDA CX-5 (2016 annual European model, 2.2 diesel, AWD, 150 HP). The car is great but I'm confused that it does not have a rearview camera, so I built a third-party camera. The problem is that the camera image rarely appears on a headunit screen. I've tried multiple independent monitors, the signal is on a headunit. Sometimes it shows the picture of the camera, but most often it only shows the normal picture of the stopwatch. I have no idea what it's up to whether it works or not. Is there anyone else's idea that I can solve the image of the camera in any backwardness? The headunit currently operates under 56.00.511 EU N operating system. Thank you in advance for your help.