I've assigned num 5 for to my Daedric Dagger and num 2 to my Blade of Woe. When I tap 2 or 5, the weapon in my sword-hand gets replaced. in order to actually dual wield, I need to open up the favorites menu, and left click/right click to make it happen.
Is there a known way, by which I can change the controls to dual wield upon tapping?