This just started happening. There is a lag when downloading PDFs. The file name Unconfirmed 999999.crdownload appears for a second or so before it switches to the intended PDF file name. I have noticed this as I download PDFs to a folder so as to import into Evernote. The above file is harvested by EN before the “switch”.
This did not happen with previous versions of Brave. It does not happen on the same web sites using FF or Chrome. I can rename the file by dragging it to the desktop.
Using Version 1.1.23 Chromium 79.0.3945.88 (Official Build) (64-Bit) on Windows 10 Pro.