Pages vs host them on Github

The static site hosted on my Pages with Pro plan seems always slower than directly hosted them on Github. It’s slower from time to first byte and total time when I tested them using webpagetest.org and I tried multiple locations.

Does your static HTML files contains links to 3rd party resources? In general all files are static, Cloudflare would keep a cache of the HTML, but if you have resources that links externally to a different hostname for files like jquery, js, css, boxicons etc, they could delay the request.