Incorrectly configured multiple default gateways can be the cause of seemingly random failures in you your system.
Viakoo runs into this fairly often and 99.5% of the time it is incorrectly configured. Multiple default gateways on a windows server are a very VERY advanced routing feature. Improper configuration of multiple default gateways will cause seemingly random network connectivity issues.
i.e. cameras disappear, cameras show as offline, cameras don't record, SAN volumes disappear, workstations cannot connect, camera views disappear from monitoring stations.
Microsoft makes it very easy to accidentally activate multiple default gateways.
If you have more than one NIC port, likely only one of them should have a default gateway.
The reason for a default gateway is to reach "The Internet" You do not usually get Internet access from your camera NIC port. Don't give it a default gateway.
Most of the time what you are trying to do is add a static or what Microsoft calls a persistent route. Here is a Microsoft support article on how to add a persistent route.
Microsoft has several nice articles on how and why to configure multiple default gateways located here:
If you have received a ticket for multiple default gateways, consult a network engineer about your network settings.