PDF still strips out Alt Text created in Word. I've tried all the functions between PDF Maker and Export tools What am I missing?

Converting Word to PDF removes Alt Text. I’ve used the Word PDF maker and all the different buttons that pop up. I’ve following the instructions I found here. I also have the same issue with Save As and Exporting to PDF. I’ve checked and unchecked so many options in the various Export / Save As tools. 

And the Alt Text still gets stripped out. What option needs to be checked, unchecked, selected, and which set of conversion options get it right? 

I am using an updated version of Adobe and Office 19.

I need to be able to explain this clearly to the entire staff as we meet the WCAG 2.1 deadline.