Yeah, that’s the name of it.
It I disable that, my network cams won’t work, I don’t think.
If that's the way they were set up, you are right. If you wanted to spend the time, you could probably configure their connections manually after disabling UPnP in both the router and the cameras.
Here's something you can do that requires little time, and that can greatly enhance your router security. Just update the router firmware:
While a firmware update is very likely to work without problems, there is always a remote chance that it will screw something up. If that happens you can reset the router to factory defaults, or install a previous version of the firmware.
You may have to reconnect your devices after the update, since internet access will be briefly interrupted.
Good luck.