Jon tart

Evening. I’ve put wires in at home for CCTV cameras. I’ve got Qvis Cognitio cameras. The engineer has been out today to connect them up and he can’t get any image out of them. All wires abd connections are sound as he tested wires. I’ve used Cat 6 cable but it’s a heavy duty one with a thin metal proctor and a plastic separator in the middle of the cable. Standard CAT 6 cable is working and we can get images with that. Why won’t this better cable work? Thanks

Cable was checked on the metre and 8 came in and no earth fault on either side. just no images

Hi wire method was correct order, as tired with cat 5 cable and it worked fine. cat 6 rj45 used. distance was 30 m and 3 m. Strsight into the Nvr thanks