I’ve been acknowledged that the snap distribution of the Skype desktop client isn’t compatible with the IBus input method(keystrokes are consumed, but input neither noticed in the pre-edit area nor in the application).
As Skype is a classic-confined, Electron application I have no idea what’s the cause.
I can confirm that ibus input doesn’t work with the skype snap. Its launcher script doesn’t appear to be using the desktop helpers that set up everything needed for ibus input to work in snaps.
In comparison, another electron-based snap (whalebird, strict confinement) does accept ibus input.
I have done some investigation and posted how to make ibus work with skype at https://forum.snapcraft.io/t/ibus-doesnt-work-with-skype-snap-on-20-04/17279.