Hello, since swapping my router firmware to "Gargoyle" the client IP addresses are ALL reported as the router within pihole 
Pihole IS working, and the router is configured to use it.
Ive asked on their forum, but they assume the user has a degree in nerdiness !!!!!
Im told I need to alter a config file, but no idea which - or what to alter...
Any ideas PLEASE ?????
I'm not familiar with Gargoyle routers. Can you send a screenshot of where you are setting the DHCP options for the DNS?
Heres the page where I configured the DNS... but from what Ive been told, the option I need to change is not available via the web interface... !
Can you send a screenshot of the DHCP section from the sidebar?
That seems to be correct then. However, the perfect solution to your problem is to use Pi-hole's built-in DHCP server.