The label text for the Custom URL setting is www.yourdomain.com, but it appears that including www. actually breaks it.
I discovered this when my Cloudflare domain was failing w/ 404 even a few hours after configuring the DNS and page rules per the docs. When I removed the www. it immediately started working.
To be more specific, I actually pasted my full URL like https://www.yourdomain.com/ which it auto truncated to just yourdomain.com, and that’s how I figured this out. Which I think means the parsing of the value may need to be fixed (in addition to the label text)- it only auto strips the prefix if it’s a full https://www., not if it’s merely www..
