if you want to use dns.yandex on Wan, you should only have one dns 77.88.8.7 if you want to stop pornography on the search engine without it being able to bypass images and video, it is good to use this and the other dns it has that are under on the same family filter only 77.88.8.7 works and the other with dns 77.88.8.3 should be skipped or not used as it does not work as it should
dns.yandex on Lan, it is not possible to log in normally on the asus routers website
otherwise I recommend dns.yandex to use as standard if you have small children at home, it has been solved with a while that parents control works with of dns filter in Lan