Google Search Couldn't fetch sitemap.txt in Cloudflare Page


I created a siite by Cloudflare Page, and created siteMap.txt in it. I got an error when I tried register siteMap.txt in GoogleSite.

I checked Firewall event, and there was nothing.

I also tested the siteMap.txt by Inspect n GoogleSite, and it iwas read with no problem. I even tried to index it, and it was successfully indexed by GoogleSite.

So, it is so weird that siteMap.txt failed to be feched only when registering as sitemap.

I appreciate your help. Thanks in advance.

Folllowing is url of siteMap.txt:

The sitemap file passed in online test: