I have a unusual problem which I have been unable to resolve and could use any assistance someone might provide. A single PC (mine) is having unbelievably slow performance for websites using Cloudflare’s service (which is all of those my company maintains). This is unlikely to be a configuration issue for those sites, as I get the same poor performance from https://www.cloudflare.com/ itself. For context, a lighthouse audit (chrome devtools) put First Contentful Paint at 48.1 seconds for Cloudflare’s home page. Looking at the network waterfall, an excessive amount of time is spent waiting for TTFB, but the content downloads are occasionally not commensurate with their relative payloads either (I see one 41kb js file that took 10s for content download).
This problem does not exist for any other device connected to the same network. The PC in question is a Windows 10 machine and does not experience similar problems with any other website or service that I am aware of. I have tried flushing and re-registering the DNS, Specifying in the network adapter settings to use cloudflare’s own DNS (both IPv4 and IPv6) and clearing Chrome’s DNS cache (though this problem exists with all browsers). No joy.
This is actually not a new problem for me, I’ve been just “dealing with it” for several months, so rest assured the PC has been restarted. Anyone out there have a clue as to what stone I should turn over?