I have the same problem: Ubuntu 20.04 LibreOffice (snap) 7.0.2.2
If I use the Appimage provided by LibreOffice (https://www.libreoffice.org/download/appimage/), version standard, fresh, the digital signing works fine.
I have the same problem:
Ubuntu 20.04
LibreOffice (snap) 7.0.2.2
If I use the Appimage provided by LibreOffice (https:/ /www.libreoffic e.org/download/ appimage/), version standard, fresh, the digital signing works fine.