XSS worm on my InfinityFree site?

I cannot imagine that either Cloudflare or our browser challenge script could cause a YouTube embed to break. In all cases, the page is just loaded by your browser and all code on it should execute normally. The whole situation sounds like it could just be a race condition with some other code on your website. Like the YouTube embed widget not working because it has trouble finding the right size to use because the CSS is not loaded in, as one example. However, it’s hard to say anything more specific without being able to reproduce the issue ourselves. At the very least, would you be willing to share your website URL so we can check it too?