Some days ago (probably after some package updates) some of my hotkeys stopped working. It is no longer possible to change the volume via the Volume up / Volume down hotkeys on my keyboard and neither is to lock the screen via STRG+ALT+L, it simply happens nothing.
When I am in the keyboard-settings of my Ubuntu and click the option for Volume down and then pressing the hotkey the hotkey is properly detected.
Does anyone have an idea how to fix this, or is it a bug?