Broken Rancher internal DNS after installing dnsmasq

Everything was working fine and services could ping / discover each other. Then I added a dnsmasq service which was supposed to be the dns and dhcp server for my home network. This seems to have broken the Rancher internal DNS though as services can no longer ping / discover each other, even on the same stack. I have removed the dnsmasq service from Rancher to no avail. I’m using Rancher 1.6. Ideas anyone ? Thanks