TTFB Not Stable When CDN is Enabled

I have a site where when I enable CDN, first time landing on a page the TTFB is 800 ms - 900m. And when I refresh the page it will jump to about 25ms to 40ms.

But If I disable or pause CDN the TTFb becomes more stable at says 250ms on both initial and multiple page refresh.

Can someone help me with sorting this out?

Thank you.

What’s the domain?

onlinebusinessconsultants.net

You’ve got Cache Everything enabled, but it’s set for what looks to be ten minutes.

Regardless of how long the cache is set for, on the first visit to an uncached resource, such as your page, Cloudflare has to get that resource from your origin server. That takes a little longer, but the next visits through that same edge server will be much faster…until the cache expires and the cycle begins again.