Find an SM that has pulled an incorrect IP from a rogue dhcp server
Go to Statistics -> ARP and copy down the MAC address under NAT Public ARP Table
Go to each access point on the site and go to Statistics -> Bridging Table
Locate the MAC you copied earlier and find it in the Bridging Table of the AP.
Once you identify which AP’s bridging table the MAC is in, it should also have an SM LUID ID associated with it and that will be your culprit.
Best fix from there is to NAT them back up (they will be bridged) and let it be their problem until they call in. You will have to release/renew everyone who pulled a bad IP after this is done.