What is the name of the domain?
What is the error number?
No specific error code - connection timeout/unreachable
What is the error message?
No error message displayed - pages simply don’t load or timeout when accessing through problematic ISP
What is the issue you’re encountering
My website works perfectly when accessed through VPN or different ISPs (Claro, Movistar, mobile data), but fails to load when accessed through my local ISP with Cloudflare proxy enabled. The issue affects both GitHub Pages and Railway deployments when proxied through Cloudflare. When I disable proxy (“DNS only”), the sites work fine with the same ISP. nslookup shows my domain resolving to Cloudflare IPs in the 104.21.x.x range, while other working Cloudflare sites (like Discord) resolve to 162.159.x.x range. This is critical as it’s a university grades portal that students need to access, and many may have the same ISP.
What feature, service or problem is this related to?
DNS not responding/updating
