I am using Firefox and Doh and today Feb-20-2019 I was not able to access your site “https://cloudflare-dns.com/help/” The message is the sight is not avaialable. However from my same workstation I can access the site via Safari so Firefox is filtering your site even with DOH turned off. I tried accessing your site directly by IP http://126.96.36.199/ but it stated not accessible via direct IP.
I am using firefox version 64 on a Mac running high sierra,
Can anyone provide an idea as to what is occurring?