Acrobat shows space above a rule as a form field--when it's not!

I used InDesign to create galleys for a book I'm producing. The text includes pullout quotes in the margins--they're created by typing text in boxes, with the paragraph style for this text having half-point rules 6 points above and below the text. I've done this many times, with no problem. This time, however, Acrobat Pro 2023 interprets the top rule as the baseline for a form field to be filled out--and indeed, I can place the cursor on it and type! I have done absolutely nothing with this file in Acrobat to tell it anything about creating form fields--so I find this puzzling and concerning. Eventually, a PDF from this project will go to a printer. If Acrobat thinks that rule indicates a form, that means there's code in the file that it's interpreting that way--and I don't want an annoyed printer barking at me because my file failed press checks. Has anyone else run across this, and have you found a fix? Searches on Adobe.com turn up only questions concerning people creating forms--not Acrobat imposing form creation on them.

Followup: I can see no way to delete this question, so I'll just report that I created a new PDF from InDesign, and that this one works correctly, as expected, with no bogus form fields. ???