Just wanting to revitalise this post ...
I too have a Swann NVR8-7400. Mine came with 4 cameras to start with, which were all hard wired directly to the NVR.
No issues so far with that as they were all recognised and are working fine.
Then I ordered 3 Reolink RLC-410 which come out of the same factory as the Swann cameras .... have forgotten the model and I'm not at home.
Those 3 cameras will not show up in the NVR as part of the system.
What I have seen is that I can either connect them via an PoE switch somewhere else on my property or directly via one of the ports on the back of the NVR and they are seen by the NVR.
What the NVR does tell me is that the password is wrong to access the camera.
I have tried to leave the password in the camera blank and also use the common ones: 000000 and 123456.
The NVR must have a hard coded password to access its own Swann models and not be able to access the Reolink because of that.
Does anyone know which password Swann might have used to make the connection?
Cheers
Tim