For weeks I kept trying to get OpenDNS to work properly with eero. I entered the IPv4 and IPv6 OpenDNS server IP addresses into eero and all seemed good. But when I using the OpenDNS test of "welcome.opendns.com" I would get errors that I was not using OpenDNS. Then I changed the DNS settings on the computers (Mac and Windows) to manual instead of automatic and entered the OpenDNS server IP addresses into each Desktop/Laptop. That sort of worked as some brewers would state it was using OpenDNS and other browsers would give the error that I am not using OpenDNS. 

Then I went into the eero app and turned off Advanced Security and Ad Blocking. That did the trick as all browsers and connected device started saying I was using OpenDNS....problem solved.....sort of as now I cannot using Advanced Security and Ad Blacking. 

So WTH is the issue with eero Advanced Security and Ad Blocking that prevents the OpenDNS servers from being used?