Doesn't work for me either. I finished the game without it anyway, the objects that can be picked up/interacted with are quite obvious most of the time.
I've tried changing my keyboard language (as I've noticed the number keys only work in dialogues with Shift on an azerty config), Autohotkey... nothing works.

I'm probably going to report a few bugs I've found like that one, maybe on the Steam forum (devs seem more active there?). None of them are game-breaking, and most fixed 'themselves'! (mostly inventory and placement bugs, nothing that can't be patched).

By the way, there's a forum for Shadows: Awakening only now.