I have 2 Hikvision IP cameras connected to an NVR. The NVR gets it's time from the NTP server without issues, but the cameras don't sync with the NVR time, I've tried setting up NTP for each one, but when I hit test I always get the "Failed to connect the test server." The default gateway on the cameras is set to the router which the NVR is connected to. Is there a setting which I am missing to make the cameras override their time settings and sync with the time from the NVR?