I am having this weird issue suddenly where 4 of 16 cameras (all dahua system, stand-alone) drop the image (but not the recording). However, if I switch the stream to "M" from "S1" it works fine for a while until you switch the view or something. Any ideas? FPS is set at 10 w/ VBR... newer NVR (about 6 months old) Cameras vary in age. The NVR provides the POE switch and so I removed the switch that I had used before. I am thinking its a power thing but just want to confirm my thinking. Any ideas?