PDF not showing in Front-End

Hi.
Using in WP 5.4.2 with Elementor.
Adding the Shortcode in design time – it shows great.
However, the front-end does not show the PDF frame.
It shows the “Full Screen” button, but below returns the “requested page not found” and the rest of the page is not rendering properly.

How is it that it works fine in design time (Elementor designer) but not in run-time in the front-end?