PDF export is missing photos and text assets

Hi everyone, I'm a little at a loss here. I've had no luck finding a solution to my specific problem, even though there are lots of similar discussions. My particular problem:  when I export an INDD file to PDF, there is one page in particular that exports without some images and text assets.

For context:  My INDD file that harbors the problem (I'll call it the Chapter file) is one of multiple that are used within an INDB. The page that has the errors on it is from an INDD file (I'll call it the Case file) linked within my Chapter file. This is done throughout the book for editing consistency and I have never seen it be an issue elsewhere. This is also a relatively new problem, within the last year.

• The Case file exports flawlessly to a PDF on its own.
• None of the images/text assets have a color applied to them, and none of them have "Overprint Fill" or "Nonprinting" attributes applied to them.
• I have tried exporting the Chapter file as an IDML in the case that it may be damaged,  and then exporting to PDF from the IDML but the specific page still exports to PDF with missing images and text assets. It is always the same ones.
• No other Case files (there are many others) in the Chapter file or in the rest of my INDB show this problem.
• Making a duplicate of the Chapter file that is not linked to the INDB does not make a difference; the Case file page still exports to PDF with the missing images and text assets.
• The PDF export type is for Print, exporting as Interactive doesn't change anything.
• I made a brand new INDD file with no styles, no assets, no properties, etc. from any of the other files. I linked the Case file into it and exported to a PDF and the same. Error. Happens. With the same images and text assets being missing.
• I have tried making a brand new Case file and remaking the layout from scratch. This didn't help.

I've attached images below looking at the Chapter file in Indesign, looking at the Case file itself in Indesign, and the page once it's been exported to PDF. Unfortunately I do have to redact most parts of these images for privacy, so all black boxes/image backgrounds are from myself. As you can see, most of the images disappear once it is exported to PDF, as does all of the figure text/figure numbers which honestly baffles me even more because those are just straight up text.

If you made it this far, thank you for reading. I've been having this problem and nothing I try seems to get close to fixing it. My current workaround is exporting the Case file on it's own as a PDF (which, once again, works fine for whatever reason) and linking that instead of the INDD file so there's no issue when I export the entire Chapter file.