1. change your DNS to
208.67.222.123 208.67.220.123
2. turn off wifi and turn on wifi
3. clear cache
sudo resolvectl flush-caches
4. check
https://www.internetbadguys.com
5. reference
https://www.opendns.com/setupguide/#familyshield
208.67.222.222 ยท 208.67.220.220