Hi, wqvant, welcome to AL forum. And what instead of inputs on the channel box, clear place? You can check inputs in Hypergraph or Hypershade, and also reset settings (channels>settings>reset to default). Also, can you post a printscreen of your channel box?

When you create a shape you get the input... if you delete the history you will loose this input! Also when you duplicate a shape with the inputs, if you don't do a special duplication with the graph connection, then you won't have the inputs on the duplicated object.

Just to understand the principle, if you create an object and you look at its imput connection in the hypershade, you will see a node and that is the input you can get in the channel box. delete history of this object, this node will disappear.

Hope that help you.
and welcome to the lounge

Mathias.

Hm, the solution is to enable history queue (the icon in image below) or from Window>Settings/Preferences>Preferences>Undo>On. 

P.S. I'll move this topic into the '3D Software'.