Some URLs blank on mobile

I have several pages created as eBook URLs. I made these as an HTML embed on desktop and a PDF button that links to the eBook asset on mobile. I realized today that some of the URLs display as blank when accessed on mobile.

For example, this URL displays normally on mobile:

But this URL appears blank on mobile:

I can’t find any differences in the eBook file size/type, the page settings, HTML code, or the link. Can anyone see what I’m missing?

Here is my site Read-Only: [LINK](Webflow - IsoTalent)
(how to share your site Read-Only link)