I have 2 Dahua IPC-HFW4300SN camera's I recently installed. I have the camera's connected to a TP-Link 8 port POE switch model TL-SG1008PE. A couple of times a week the video quits working on the camera's but I can still log into them. If I go to the POE switch and unplug the cat-5 and plug it back in..(power cycle the camera) the video starts working again. Any idea on what could be causing this issue?