Wonder if the ISP is restricting some of the Cloudflare IPs or even more.
There were cases where ISPs blocked Cloudflare IPs.
Unfortunately, I am afraid you cannot change the proxied IP address. Eventually it will change overtime, but that’s something which I am afraid we cannot affect.
I’d suggest reaching out to the ISP provider for more detailed information.
Yes, currently Cloudflare is in DNS-only, as it will not work for some customers otherways.
May be the ISP is restricting some of the Cloudflare IP, and I understand it can change overtime, but:
If client’s IP is in Spain, why is Cloudflare replying with a IP from Colombia? It’s 5,000 miles away, shouldn’t anycast choose a location nearer the requester?
We’ve been trusting Cloudflare for 10 years now, with nothing but benefits. If something went wrong, 99,99% was not Cloudflare’s fault. But if a web can go down anytime unpredictably with oddly assigned proxied IPs we cannot trust no more.