For "centuries" commenting selected source code lines, which was "Cmd+/" on US keyboards was "Cmd+Shift+7" on German keyboards.
Now (Xcode 13.1 on macOS 12.0.1) it is "Cmd-ß".
Indentation (US keyboards: "Cmd+[" and "Cmd+]") has moved from "Cmd+Alt+5" and "Cmd+Alt+6" to "Cmd+Ö" and "Cmd+Ä". This is strange since it does not make any sense. On German keyboards you reach "/", "[" and "]" using the keys 5, 6, 7 with Shift or Alt modifiers.
And the really bad thing is: You can't change it. If you change the key bindings in the preferences, it has no effect.
When I'm coding right now, I get always confused typing the shortcuts, I used for so many years, and seeing them not working anymore. Please, I want them back!