I'm having the same problem as this person
When I first embed a draw.io diagram into the page, I have the option to change settings, like the toolbar, lightbox, etc, by clicking the little pencil icon below the diagram.


However after I have published the page, if I go back to edit the page and click this icon, it opens the draw.io macro settings but then immediately redirects to editing the diagram itself. I don't want to change the diagram, I want to change the viewer settings.
I have the toolbar hidden, so I can't get into the macro settings that way, and I can't edit the macro to show the toolbar because of this bug.