Adobe Reader DC does not print black. I have version 2019.021.20061. I have a Windows 10 machine printing to a Canon MX922 printer. I have no problems printing from other applications. I checked for updates and mine is current.
When I send a document to print, it looks fine onscreen, but only a few colors (a logo) print. No black at all, either in the original or when I fill & sign. This happens with all PDFs.