Ed,
If you had the camera on the main network with a PoE Switch, I would check the gateway to match your current modem/router, I see that you have it on a Hikvision recorder with a built-in PoE, recorders with a built-in PoE switch would completely isolate the camera from what we call the "Main Network" one trick that you can do is set your LAN of your computer to the same IP scheme as the internal PoE switch's then connect the LAN of your computer to the PoE port of the NVR, once you have done so this will allow you to check with the config tool the cameras IP and change its parameters, what I have seen in many cases is that setting the cameras to a static IP will create issues as the internal PoE switch will attempt to provide the camera with an IP address, I would set the camera to DHCP then use the config tool while the camera is connected to the internal PoE switch and the computer is also connected to the internal PoE switch, then manually add the camera.
With Onvif there are some issues when it comes to compatibility when it comes to firmware, in many cases where the camera either does not connect or connects and there is no image, one can upgrade or downgrade either the camera or recorder until the correct combination is achieved.
I wish you well, if you have any questions please let me know and I will do my best to assist you.