I am using the flatpak of SCID 5.0.2 on Debian Linux (GNOME desktop) and the keyboard shortcuts rarely work. In particular the "save" (ctrl-s) and "undo" (ctrl-z) shortcuts which would be very useful when exploring opening variations using CaissaBase in a tree window frequently do nothing. The drop down menu options work fine but that is less efficient than using a keyboard shortcut.