pixellated video

Hi, I have 4 cameras set up and they have been ok so far but very recently, I am getting pixelation/corruption of some sort. The NVR system is a Dahua but rebranded as something else. Any ideas what could cause the issue as shown in the video below. FPS = 25 VBR quality = 6 Thanks!

Hi, I have a pixellated video capture from time to time, and don't know why. It happened on all three of my IP cameras Dahua 2MP HDB3200CN, 2MP HFW3200S, and 1.3 MP HFW 2100S on an intermittent basis. It will be fine then become pixellated for maybe a second and then go back to normal. I...