opening files in illustrator edited using Foxit

I hope someone can help.

I work with a client and create posters etc using illustrator and send as a PDF. They occasionally make edits using FoxIt software (https://www.foxit.com/) and send back to me by email. When I open the attachments using Adobe Acrobat, I see the edited file. BUT when I save the file and open in Illustrator, I see the original file I created, not the new edited file. The files have been saved with a new description. See attached image. The screen on the right shows the new edited file (Adobe Acrobat) while the screen on the left (illustrator) show me opening the saved file, and it is the original before editing. My client has sent the same edited file to a colleague, and they are able to open the edited file and see it correctly.  Thank you.