You can only allocate to like 3 options the first time. Inner circle working it's way outwards... think like Final Fantasy or DAII how you can't get all the skills until you upgrade earlier ones.
So... basically pick the vigor regen one. Click on it. Then hit enter / select enter.
Tried this. Have hardiness highlighted, pressed enter (as well as every other keyboard key) and nothing happens.
Also, I have not rebound any of the keys.