The cameras, nvr's, and Poe switches I am using are a generic brand but quality. I usually pull Cat6. For this one project, I pulled
cat5e with cat5e connectors. But same problems arise on my cat6 runs. In my setups, all cams either go directly to a Poe switch where the gigabit uplink goes to NVR and a 10/100 port uploads to Internet or cams go directly to a Poe nvr and the standalone port uploads to Internet. No bs in between. The crimpers, they get the job done but are not the best. Connections obviously work. They seem solid.
I should also mention, it's not one specific camera, it's random cameras. And the cam(s) will remain off until there is a quick basic power cycle. Not something I want to resort to. It's not stable.
Could it be bandwidth overload to the nvr? Cams record at 2 megapixels, at 25fps, 24/7. If anything, what else could it be?