1: Change the language preferences so that Windows is using a Japanese keyboard
1.1: In Windows - go to Settings
1.2: Go to "Time & Language"
1.3: Go to "Language" tab
1.4: Click on the topmost "Preferred languages"
1.5: Click on "Add a keyboard"
1.6: Select "Japanese: QUERTY"
1.7' Cycles through languages using the Windows Key and Spacebar, and select "English (United Kingdom Japanese Keyboard"

2: Start DayZ
3: Load a server
4: Try using Caps Lock to talk
5: Attempt to change the keybinding for voice chat

Result:
1: Voice chat will not work and the icon will remain on the screen until entering the esc menu.
2: Player cannot change the voice chat key binding.

Expected:
Regardless of the language or keyboard preferences set in Windows, DayZ keyboard bindings will work correctly.

I have not checked it with other keyboard preferences, and I have also not checked whether this affects changing other key bindings.

This did happen to me several Windows updates before, but I usually switch between keyboard preferences a lot, and so I perhaps thought it was a random glitch before.

Edit: This only seems to occur if the default keybinding is Caps Lock.