If you have just added your site on CF, it’s normal, you just have to wait some minutes.
Your server is redirecting incoming traffic on port 80 to https. You need to disable this if you want to use the flexible mode (which is not recommended, anyway)
It still does not work; I have set up another subdomain for Google sites from Google domain, after waiting for 10-15 minutes, that URL is up and running.
Should I make some change in Cloudflare to support Google Site? I have another site running in Gitlab pages, which works correctly.
A 525 means you don’t have a valid SSL certificate on your web server. You’re probably running Full (Strict) SSL.
The Too Many Redirects in your Flexible mode meant the website was redirecting to HTTPS, but Flexible mode needs to operate in HTTP on your web server, without a redirect to HTTPS. In this case, it’s better to just leave SSL set to Off.
Hi @cico, I think the input on this thread netted it out pretty well. I don’t think you’ll get this working without addressing the redirect @francesco points out and the certificate issues @sdayman mentioned. I see a cert on the origin, but with an invalid name.