Hi i am pretty new to this aswell, actually just added the first inventory item in the project I am working on yesterday. So if I am wrong probably one of the more experienced AGS users can correct me.
To me it sounds like you might have forgotten to set a sprite for the mouse cursor image, the mouse cursor image is the one used when you clicked on the object and turns the mouse cursor into the image you have choosen for the object, you will also have to set a cursor hotspot on the sprite image to be able to klick anywhere with it ( or if its automaticly is placed in the upper left corner, i dont know ).
For me using AGS 3.2, i just click on: Inventory Items> then click on the item you have problems with and look below under Appearance: there you will fine image setting ( wich is the image of the object displayd in the inventory screen ) and then CursorImage setting wich is the the image to be displayed as mousepointer when you have the clicken on the item.
Then just set the cursor hotspot by clicken on the new image.
To me it sounds like you might have forgotten to set a sprite for the mouse cursor image, the mouse cursor image is the one used when you clicked on the object and turns the mouse cursor into the image you have choosen for the object, you will also have to set a cursor hotspot on the sprite image to be able to klick anywhere with it ( or if its automaticly is placed in the upper left corner, i dont know ).
For me using AGS 3.2, i just click on: Inventory Items> then click on the item you have problems with and look below under Appearance: there you will fine image setting ( wich is the image of the object displayd in the inventory screen ) and then CursorImage setting wich is the the image to be displayed as mousepointer when you have the clicken on the item.
Then just set the cursor hotspot by clicken on the new image.