My gut feeling would be that it's a data problem, and the first straw I would grab at is home made cables?
Or less than top quality cable? e.g. CCA
The type of cable tester that most people are able to afford and use only tests for continuity / correct pin-out.
High-res video equals high data rates which is challenging for the cable and the crimping / connections.
Perhaps you can test by either fetching the camera to the NVR and using a short manufactured patch lead, or 'chucking in' a temporary bought lead to the camera.
Its a high quality cable plugged into a Netgear GS110TP (using POE), its not displaying any dropped packets and i changed the port its plugged into with no effect, i had a DS-2CD2085FWD-I on the same cables ect before this camera and it was fine, i suspect the camera is faulty.
Just a note its fine at night not sure if that means anything?
I can try another cable but i suspect it will be the same. The other two DS-2CD2386G2-IU look fine but do not cover where car would go so its not easy to compare or easy to swap them around.