I am also using an NVR and Sighthound solution and have avoided all the IP class/virtual host issues by using a separate POE switch and connecting one of these ports to port 1 on my NVR. Everything is configured for static IP addresses (all on the same subnet).
The NVR records the main, full resolution 4K h.265 streams 24/7, while Sighthound running on a Mac Mini records the secondary low resolution h.264 encoded streams (and provides all my notifications).
Just a reminder that Sighthound only records h.264, and I had some "could not connect" camera issues at one time where I had set up Sighthound to accidentally process an h.265 stream.
-Tony