some urls seem to be blocked by xfinity wiki, but mobile network can access it

in xfinity wifi, can't open a link, but when switching to mobile xfinity or hotspot, it's working.

already tried clean-cache, reboot, switching different browsers in different devices (laptop, phone), same problem.

i have a bunch of URLs as examples, and also "openssl s_client -connect" output about certificate info.

have tried customer service in live chat, phone, etc. not helpful at all, live chat representative didn't forward the info, phone representative ask me to spell out long URLs.

need a written form to provide further info