I've changed my widget in the web editor, but when I open the widget URL, my changes aren't visible
Have you updated the shared copy?
When modifying a widget, the changes are kept private until you decide to update the shared copy.
You can see that the widget has been changed because of the change message and the appearance of the Update Shared Copy link below the shortcode. You can press the link at any time.
When you press the Done button while changes have been made which haven't yet been shared, we'll ask you whether you want to update the shared copy.
If you navigate away from the editor in another way, your changes won't be shared yet. But they will be saved. To update the shared copy, open the widget in the editor and press the Update Shared Copy link at any time.