Hi Jeff... You have "optimize PDF files" enabled in your editorial -> application settings -> asset settings -> Optimize new PDF files. Optimizing PDF files removes a lot of information in order to make them smaller and flatter.
If you turn this off, even temporarily, in order to upload your file, it should fix the issue.
I tested it, and when the "Optimize PDF" setting turned off, the PDF keeps the fillable information, and when a user downloads that form, it will allow them to fill it out.
You can then turn back on this setting if you want other PDF files to be optimized.
To further test to see if my form maybe was bad. I downloaded a Fillible PDF Sample from a website, uploaded it, and when I download it, all the fields are gone. http://www.tdtnews.com/pdf_e02a5b5e-4f3d-11e9-8478-8be345532650.html
I had no idea. Thank you for letting me know, this totally makes sense.
Customer support service by UserEcho