Tearing my hair out over this issue. I have configured my mailing lists appropriately, tested the form on the editor (which did successfully send me an email), but on the live site the block is completely missing. There are no error messages, and in the "storage" tab, it even shows "disconnect" as an option at the bottom, implying it is connected properly.
I have no custom CSS or any non-squarespace-editor code whatsoever.
Anyone else run into this issue? People who bought from me are successfully showing up in my list, so I know it's at least configured to accept new entries.
The screencap below is what I see on the editor, but if you navigate to the live site, you'll see it's just a blank background image.