Modifier keys not working for movement

[Quadnick.]

I put 167 hours into this game using RCtrl as my move forward key, but it's not working now that I've returned to the game. Nothing happens when I press it. Neither of the shift keys work either; though alt does. These buttons work for other things, like attacking. Just not for movement. Happens in a new game with my TW3 documents folder empty too, so I don't think it's mod related. I used to use a fair amount of mods, but this is on a fresh install.

Also, I didn't realize there were subforums until after posting, so I feel I should mention that this is the The Witcher 3, Steam version.