Google search console couldn't fetch sitemap.xml in my cloudflare pages

Hi.
as title says, Google Search Console cannot fetch sitemap.xml in my Cloudflare pages

my site url : https://iidx.pages.dev/
sitemap url : https://iidx.pages.dev/sitemap.xml

I googled about it, and did a few things. but nothing worked at all.
any suggestions? thank you.