My DHCP setting wasn’t setting the nameservers to OpenNIC because the browser took me to an ISP search page instead of "Server not found".

/etc/resolv.conf said it was generated by Connection Manager.

I finally found this thread and figured out how to set the nameservers for each connection by using connmanctl. Then, I restarted the connman.service. Now, the OpenNIC IP addresses are in /etc/resolv.conf, and my ISP does not hijack my DNS :-)

Also, identi.ca is back. I was just about to use microca.st.