On ubuntu 18.10, I am using ibus as an keyboard input method system and use Korean.
When I install vscode as a snap application for example, I can’t use Korean (can use only English).
What’s more, fonts installed on system can’t be used as well.
However, no similar issue occurs on vscode installed by .deb file.
So the problem is keyboard input method (and probably access to some other system resources like fonts) does not properly work when using snap apps, at least on ubuntu 18.10.