Check the following link to see if you use OpenDNS http://welcome.opendns.com/ After you confirmed you use OpenDNS if a domain is not being blocked check and see if the domain is blocked on this page

Jul 18, 2020 Setup Guide | OpenDNS Thanks for choosing OpenDNS! To get started, you’ll need to set up one or more of your devices to use OpenDNS’s DNS nameservers. For instructions on how to do this, choose your device type from one of the categories below. Use OpenDNS

Using OpenDNS with DD-WRT installed on your WNR3500L router is an easy way to control which websites that can be accessed on all Internet-connected devices in your home, from laptop and desktop computers to gaming consoles and mobile phones.

OpenDNS has huge caches, which is one reason OpenDNS makes your Internet experience faster. With CacheCheck, you can check what OpenDNS customers see when they request a domain. If there's something amiss, you may refresh OpenDNS's cache for that domain. Enter a domain name to check: Enter the code: OpenDNS Updater shows not using opendns – OpenDNS

Configuring OpenDNS - Internet - Internet Forum - Cox

Test Your DNS Servers - RouterSecurity.org Jun 14, 2020 Using DNS over HTTPS (DoH) with OpenDNS – OpenDNS Jul 18, 2020 Setup Guide | OpenDNS