A CMS table has a field of type "link". This link field is used for "mailto:..." URLs, NOTfor URLs of type "http://....".
When trying to bind a dynamic item element to the URL field using "Get URL from" it shows "no field available".
As soon as at least one record in the CMS table has a "http://..." URL in the "link" field, the link field to bind to is shown in the editor.
It looks like as Webflow checks "link" fields in the CMS for at least one "http://..." URL before it makes it available for binding with an HTML element using "Get URL from". I believe it shouldn't.