How are you trying to connect this camera to your NVR? directly to the NVR PoE ports or remotely over your local network via a separate PoE switch/injector?
How many cameras do you already have connected to the NVR?
If you are trying to connect the camera directly to the PoE ports on the NVR, did have the camera online via a separate PoE device before moving it to the NVR or did you plug it into the NVR straight out the box?