When creating a workflow, the "attachment" functionality (i.e. associating an existing LdS to an element of the workflow) does not make any changes. It shows a pop-up with the list of your LdS that are compliant with the corresponding workflow element... but the state of that element does not change. A similar situation happen when editing a project that follows an existing workflow (you cannot change the LdS already attached to the workflow element when the project was "implemented")
When creating a workflow, the "attachment" functionality (i.e. associating an existing LdS to an element of the workflow) does not make any changes. It shows a pop-up with the list of your LdS that are compliant with the corresponding workflow element... but the state of that element does not change. A similar situation happen when editing a project that follows an existing workflow (you cannot change the LdS already attached to the workflow element when the project was "implemented")