If SADP isn't picking up the camera - it's not powered up and connected, unless this was when you had the camera IP address set to 192.168.254.1 in which case there will be a duplicate IP address.
You cannot use 192.168.254.1 as the camera IP address, as it's the address of the NVR PoE interface. I'm assuming you haven't changed that from its default value.
For the same reason - you cannot assign NVR channel D1 to use 192.168.254.1 - that is not valid.
Suggestion :
Modify the IP address assigned to NVR channel D1 to be 192.168.254.2
And this requires that SADP finds the camera - if it doesn't when on the NVR, can you power the camera when it's connected to the LAN so SADP can find it?
Change the camera IP address to be 192.168.254.2 and connect it to NVR PoE channel D1
Set the password in NVR channel D1 to be the admin password of the camera.