Only thing I can think of is try a bios update, if there is no update then you may be able to re flash it with your current bios as it may be corrupt, failing that it may be worth emailing the manufacturer.
May be worth checking the keyboard layout in
How to add a keyboard layout in Windows 10
Click on the Start Menu. ...
Click on Settings.
Click on Time & language.
Click on Region & language.
Click on the language you wish to add a keyboard layout to.
Click on Options.
Click on Add a keyboard.
Click on the keyboard you want to add.