It'll scan them; ours don't get a whole lot of information but it knows they exist. There's a few things that may be set wrong. But, here is the best place to start.
https://www.lansweeper.com/knowledgebase/how-to-troubleshoot-devices-with-the-device-tester/
I would check that Lansweeper can talk to the camera VLAN, that you can either ping to that VLAN or that you uncheck pinging them before scanning. And check that if there is any credentials needed that they are supplied.
-Kris
