When you make geometry changes or edits to weldments, you can automatically update cut lists by right-clicking the cut list and clicking Update Automatically.
Use this option when you add new features, such as extruded plates or 3D bounding boxes, edit existing features, or rebuild the model. This updates the model's custom properties and internal supporting data, preventing custom property errors.
To turn off Update Automatically, click Options 
(Standard toolbar). On the Document Properties tab, click Weldments and select Automatically update cut lists.
You can set other weldment options from the Weldments page, including Create Cut Lists Automatically, which previously appeared on the Cut list shortcut menu as Automatic. This automatically groups similar bodies together in one cut list folder.