Steering.nextdns.io - Let's Encrypt
Glancing at https://steering.nextdns.io and getting a cert error and can't continue due to HSTS. Found it from trying to resolve dns.nextdns.io, dns1.nextdns.io, and dns2.nextdns.io. Looks like the SAN names on your nextdns.io cert from Let's Encrypt has most other subdomains and wildcards minus *.steering.nextdns.io and steering.nextdns.io.
Not sure if that is by design or not.