Switching language with the interface does work, but a favorite way (at least in terms of speed) is using Super+Space, which works perfectly after authorization. But after suspending a system and trying to log in, it stays with the same language, which was selected before suspending, so it can’t be changed with shortcut (the animation of selecting between languages icons runs, but there is no effect) and the only one way to log in - switch it through a button on top bar
That shortcut is likely managed by the desktop environment, and thus it may only be used when it is running, so after logging in.
Adding to @maycne.sonahoz comment
- you would have have activate the locale in
- and you would have to build the locale using locale-gen command
That is expected behavior - you cannot switch language mid-session - which is what you get after suspending.