Bug with WP 4.7.1 PDF Thumbnails

I have a Pod setup with a File / Image / Video field.

When a user is adding content in the CPT, and they upload a PDF into that field, the URL shows a .jpg extension on the file instead of a .PDF (thus displaying the jpg thumbnail in the browser when clicked, rather than linking to the PDF)

This only happens for PDF’s that have been uploaded within WP 4.7, where a thumbnail has been generated. PDF’s uploaded prior to 4.7 (that still have the generic WP gray icon for a PDF file) have the correct .pdf file extension in the URL.