Please tell me the typical reason why this happens.

bug

#1

Hello.

I use ClouldFlare, and I have the following problems.

  1. During use, certain sites in Korea are often blocked by sso.sitename.com

  2. Some Korean programs fail to update.

The default DNS of Korea ISP works well.
Please tell me the typical reason why this happens.


#2

Is this regarding the 1.1.1.1 resolver, or miscellaneous websites that you think are using Cloudflare?