Yeah, definitely sounds like the cameras are shot then. Water getting in one of the ports still seems like the likely culprit, but doing what you did should typically be enough. Did you protect the other two ends of the pigtail cord as well? The reset button and DC plug?

If any of my connections are going to be anywhere but inside the walls, I actually like to use marine grade heat shrink tubing like this, just to be really safe.

I'd start a ticket with their support to get that ball rolling. At least you're still under warranty.