Site not caching, always getting `cf-cache-status: DYNAMIC`

Hi, I have a blog-like site made with Remix.run and I’m using the Cloudflare CDN to cache it but at the moment it’s not being cached for reasons unknown to me. My cache-control headers are public, max-age=21600, stale-while-revalidate=3600, stale-if-error=3600. I’ve turned on a page rule for [mydomain].com with “Cache level” set to “Cache everything” and “Edge cache TTL” to “3 hours” yet I always see cf-cache-status: DYNAMIC everytime in the response headers. I’ve checked the documentation and I’m pretty sure I hit all of the requirements for caching. Not sure what I’m doing wrong.

What’s the domain?

Its https://julesblom.com/

The only thing that catches my eye is the cache control setting of immutable, which sounds like this thread:

% curl -svo /dev/null "https://julesblom.com/build/_assets/favicon-YTJ4CEOC.svg" 2>&1 | grep cache-control
< cache-control: public, max-age=31536000, immutable