I have created BIOS password. I use Dvorak layout. Though I switch my keyboard layout to Qwerty and restart while typing password with different layout. There is no change. If we see in case of OS while logining in, different keyboard layout matters. What's the reason behind it?

I have created a BIOS password. I use the Dvorak keyboard layout. When I switch my keyboard layout to Qwerty and restart, and then type password in with the different layout, there is no change. However, when I'm logged into my OS, having a different keyboard layout matters. What's going on here?