Cache file and Cloudflare

I installed the Cache Enable plugin for hours and I notice that the plugin generating the cache file really slow and not all cache file pull to CDN server. Now the CDN service provider is Cloudflare.

The biggest problem is the index, when client hit the index of my website I saw there is an index cache file but the CDN server not cached and serve original to client side.

here is the URL
https://www.williamtai.moe/

https://www.ads-software.com/plugins/cache-enabler/