So - we were going to go thru all of those motions as well until we pulled a "hail mary"....instead of submitting from a Windows-based computer, we redid the entire application from a Macbook, BOOM - accepted it without issues AND was able to sign "digitally" (was our actual signatures, something Macs allow when filling a PDF.
Thanks for responding regardless! I'm sure this will help others facing the same issues!