You can check your cache header and any bypass cache rule.
Cloudflare does not cache the resource when:
The Cache-Control header is set to private, no-store, no-cache, or max-age=0.
The Set-Cookie header exists.
Cloudflare only caches resources within the Cloudflare data center that serve the request. Cloudflare does not cache off-site or third-party resources, such as Facebook or Flickr, or content hosted on unproxied (grey-clouded) DNS records.
We highly encourage you to read more about Cloudflare’s Default Cache Behavior · Cloudflare Cache (CDN) Default Cache Behavior) to understand Cloudflare Cache Behavior.
Please note that setting Edge cache TTL will override the default cache behavior (standard caching) for static files and overrides cache instructions sent by the origin web server. It will also cache non-static assets.
You can create a Cache Rules with Edge Cache TTL. Please kindly find the instruction at Create Edge Cache TTL page rules · Cloudflare Cache (CDN) Cache Rules settings).