Parent Elements Disappearing

Indesign 2025 (21.1)

Mac OS 13.7.8

I'm posting on behalf of a contact, so I can't share the source file.

Problem:

My contact has had issues where one of his credit lines on any given spread (the text that runs up parallel to the gutter in the screenshot) disappears when he overrides the item to update the text and later shuffles the pages to reorder his articles. There should be two on either side of the gutter. The credits remain on the parent pages, and the text still appears when he exports to PDF. Reapplying the parents to the pages in question doesn't resolve the issue. The information is still there, but how to prevent it is a mystery to me.

I've figured out how to reset the credit after the fact (Pages Panel > Parent Pages > Remove All Local Overrides). My two main questions are what is happening here, and is there a way to adjust the InDesign file to prevent it? 

Thank you!