Device scanning - worked - then stopped

[presgar]

I initially added 1 network range (192.168.54.1 - 192.168.54.254) after upgrading to 4.0. It worked and found routers/switches/ip phones on this subnet. I then added a few more ranges and selected scan now but nothing new has populated? Do I need to restart the service every time I add a new subnet and choose scan now? How can I tell if there is a problem scanning the additional subnets? I used same credentials as first subnet. Is there a log?

[Hemoco]

You can click the "scan all enabled ranges now"
Make sure the range is enabled.
On http://127.0.0.1:9524 you can see the ip scanning queue size