When presented with welcome/lock screen of Windows, the keyboard layout will revert to the system default layout of VDA on windows station. This is particularly problematic when changing passwords.
This is by design of Windows system, Windows end users to use a default input language for Welcome screen. Generally, it’s same as the current user’s settings.
To check your default input language on Welcome screen, go to Settings -> Region -> Administrative -> Copy settings…
To change the setting, you’ll need to change the current user’s international setting first.