Argh! Ubuntu VS Code Keyboard Shortcut Ctrl+Shift+E

Set env variable GTK_IM_MODULE=xim

Launch from Desktop file

add it to Code's .desktop
e.g. for vscode installed via snap; add it to EXEC sections (two places): /var/lib/snapd/desktop/applications/code_code.desktop

Launch from shell

add alias to your .bashrc / .zshrc

alias code="GTK_IM_MODULE=xim code"

Ref.
https://code.visualstudio.com/shortcuts/keyboard-shortcuts-linux.pdf
https://github.com/microsoft/vscode/issues/48480#issuecomment-413793736