Every time I reinstall Ubuntu, I am faced with the same issue. Whenever I press Ctrl+. in Visual Studio Code, I get an underscored letter "e" instead of the expected refactoring menu. And it takes me a while to remember the solution: running ibus-setup and removing emoji keyboard shortcuts.
However, there is also a scriptable solution. Just use gsettings and remove hotkeys from the command line.
gsettings set org.freedesktop.ibus.panel.emoji hotkey "[]"
gsettings set org.freedesktop.ibus.panel.emoji unicode-hotkey "[]"