Export to PDF does not include all assets

I have tried to export my file in multiple ways, and it is still not including all assets in the PDF download. The PNG works, but the PDF does not. I also tried to open this file in Illustrator, but the file does NOT appear in the Adobe cloud even though it is there.

This is a HUGE issue as I need to release this file for printing. 

File name: Arcolian Dental Arts Society Christmas Invite Response Card 2026

I have tried for two days to attach files to show the issue - but they will not attach. That might also be a bug. 

I have instead included links to screen shots here:
Missing Assets:  Invite, Response Card

Correct Appearence: Invite, Response Card