In 11.11 keyboard settings there are
Move window to workspace N options (N is the workspace number). But they do not work.
Is there a way to bind key for moving window to a specific workspace/viewport?
That's either a bug or a consequence of a tweaked environment.
To verify the keyboard shortcut visit the gear in the upper right hand corner,
select system settings -> keyboard -> shortcuts -> navigation.
To reset unity to it's defaults:
Once that's done:
After clarifying the bug with the user. I found out that this is actually a known bug.
It looks like it's getting lost in the wishlist status. I would recommend filing a new bug to bring fresh attention to it. I agree that it's a bug. If it isn't an option then it should be removed from Navigation shortcuts to begin with. I think I will to, this would be very useful.