Quick Add not uploading files

When I try to use the “quick add” option from the tinymce editor, files are not correctly uploaded. I notice that when I choose a file, the filename is surrounded by ||| pipes. Then when I click on the download link in the page or article, I get a “filenotfound.txt”. If I go to the Downloads Manager in the wordpress backend and take a look at the single download package, I see an error message about the file not being uploaded correctly. If I then upload the file again there from the backend, it gets uploaded correctly and I can update the package.

https://wordpress.org/plugins/download-manager/