If you know how to switch DNS servers in your OS try US Level 3 servers. 4.2.2.1, 4.2.2.2, 4.2.2.3, 4.2.2.4, 4.2.2.5, 4.2.2.6.
Sometimes DNS servers get flakey. Cloudfare DNS is 1.1.1.1, 1.0.0.1 and google DNS is 8.8.8.8, 8.8.4.4. Might be best to avoid them atm
A neat program for windows to find the fastest servers and set them is DNSJumper. It's free
https://www.sordum.org/7952/dns-jumper-v2-2/