Evernote 10 fails to save PDF back into the note.
Earlier versions of EN used to support saving an altered PDF file back into its EN note by simply asking if you wanted to save the file and then if answered in the affirmative (yes or save) it automatically saved it back into the original note, thereby updated that note's contents.
In this latest Evernote release (v 10.5.7 build 2171 running on Windows 10 64bit) following opening an embedded PDF (opened from an EN note and launching it in PDF editor, i.e., Adobe Acrobat Pro) and editing, modifying, or changing the PDF, when closing the PDF and choosing "yes" to save, the only option is to save it as a new file. This is huge PITA and defeats the purpose of major advantage to using Evernote to manage PDFs.