The 12V power supply fed through the pig tail and the 48V from the Ethernet PoE cable are not treated the same in the electronics of the camera. Therefore it is possible to have different electronics behaviour when you switch from the 12V to the 48V. The problem is poor supply regulation of the electronic chips in the camera depending on the current drawn from the power supply. To prove you this (I have seen what I am about to describe), if you measure the current drawn from the power supply with an oscilloscope (an instrument not widely available to consumers) you will notice small spikes of current increase of about a few microamps at the frequency of the pixels pulsating . These spikes create a tiny votage drop in the electronics and affect especially the sensor voltage stability. This in turn is interpeted by the sensor digitisation electronics as a light intensity variation and hence you see the pixels pulsating. The effect may be visible either in specific areas of the image starting from the top or the left side of the image OR the whole image. The current drawn from the camera CPU when it creates the keyframe is also increased because the CPU uses more processing power at each key frame creation. If you increase the key frame creation at more than 2x or 4x times the frame rate then you only postopone the appearance of the effect (i.e. decrease the frequency of the pulsating appearing) and our human eye can not perceive it. If you look very carefully you will be able to see it.
Conclusion: The pulsating of pixels is not interference, as many have already correctly mentioned. If it occurs then you should claim a replacement of the camera as being defective. The problem is that if they replace it wth another camera from the same production lot, most probably you will have the same effect because the problem is poor selection of components (usually regulating capacitors in the camera).
Conclusion: The pulsating of pixels is not interference, as many have already correctly mentioned. If it occurs then you should claim a replacement of the camera as being defective. The problem is that if they replace it wth another camera from the same production lot, most probably you will have the same effect because the problem is poor selection of components (usually regulating capacitors in the camera).