I will post this PM response here as well as we have been working on this thing for a week. Anyone else with a good idea is welcome!!
For a day, turn off the cameras and see if this is the issue. Start eliminating network connected items until you find it. Maybe look at inserting a sub-network for just the cameras, and bridge that to the main network. My guess is that it is the wireless cameras as they take lots of network traffic space to operate.