Unfortunately there’s no way for us to tell without reviewing the actual images. Or at the very least, providing us some additional information like:
How were they shot?
How were they acquired by your computer system, and what file format were they when they were put into your computer system?
What applications were you using to work with them, what did you do those images when you were working with them, and what file format(s) were they in when you were done working with them?
How did you create your PDF, and what program(s) did you use to create the PDFs?
Where and how is Acrobat telling you your images are generated AI images, and what impact does that have with what you want to do with your PDFs?
We’re happy to try and help, but you’ve got to let us know answers to these questions before we can help you.