i assume you have more than one email address. Test by repeating the steps and send something to your other email address.

OK as you suggested: I sent the email to another person with a gmail account and attached the PDF. The PDF info appeared again as wording at the end of that email rather than as an attachment. I sent the same PDF to a non gmail account and that appeared as a true attachment and not added to the wording in the email at the end. So from this I assume this is a gmail issue? Any suggestions on what to say to Google about this issue?

Let me send myself a pdf via gmail to my hotmail account. I'm getting something from this page to test with. https://www.irs.gov/downloads/irs-pdf

Google is going to blame you or Firefox.  ;-)) Did you try the same steps in another browser? You need to come with proof of the issue. Maybe they will allow you to send them a test pdf. I have no issues with sending a pdf from my gmail to hotmail. see screenshots i don't have another gmail account to test with. This is something they may ask you to do.

Just have another gmail account send you screenshots of what they are getting.