I recently set up a Pi-Hole for my home network. It's set up as DHCP server for the router at home, so all devices should be covered by the Pi-Hole.
Network overview - Number of queries should be greater than 0.
Trying nslookup on a blacklisted site (flurry.com) should return 0.0.0.0
It is not zero only for one device, all other devices are showing 0 queries. The "Uses pi hole" checkmark is marked in all devices in the network, but they are also colored red as they have never queried the PiHole.
nslookup on blacklisted site returns the actual site (I can access it on my browser).