Thank you for your detail answer first of all.
Then, let me have a question about the attachment urls related to the license.
Actually, I have two sites, one is for development, the other is for staging. But they have different licence. One is "Free" (because it passed the trial period), the other is "Enterprise marketing solution".
In the development server, the attachment urls between the page builder and live site are same, but the staging server has different urls. I compared the most config & settings. But I can't figure out why the staging server has different urls.
Does the license affect the attachment url?
Thanks in advance,