Can't get camera to connect to NVR via POE port.

I have a DS-7616NI-SP (fw V3.1.0) and a DS-2CD2345-I (fw V5.3.6) that I had connected via lan and was working fine. I am just rearranging things and trying to get the cam to operate direct from NVR port however it is not happening. I read the thread on issues with newer firmwares and syncing passwords so have changed the cam password so it is the same as the NVR but that has not resolved it.

Any suggestions on what to try next? I have an "@" in the password, can that be an issue?