I have yet encountered a residential ISP that doesn't have DNS issues. So what is the fix? Setup your own DNS server at home (good practice and more secure). But an easy fix is to use Google DNS. I have tried and seems to work well.
Just change your DNS settings to use Primary 8.8.8.8 Secondary 8.8.4.4
No real security risk since they are tracking your searches away :)
Need more security … check out Simple DNS Crypt
Need protection from Adware … use a custom host file
https://someonewhocares.org/hosts/ current
https://github.com/StevenBlack/hosts current
http://winhelp2002.mvps.org/hosts.htm 2018
DNS Tool – manage DNS