Drag and Drop Issues

You didn't get any answers, and the reason may be that we do not understand the problem at all. 

This is what I understood so far:

• You have 5 drag sources (not sure if those are red or blue, from the last screenshot they seem to be red).
• You have 5 drop targets which are blue
• You do not want to have anything happen after submitting, but you don't tell whether you have a submit button? Or did you activate Auto-Submit, which will only work in case of completion of all the dragging in a correct way. How will the learner see that it was correct: there is no feedback, and no action is happening.
• A D&D object can NOT be set to an action at all, as you told: 'Each droppable object is set up to No Action'. If you mean the Object actions, they are linked with a drag action from a drag source to a drop target. But since you already told that dropped non-correct drag sources are sent back, those object actions have not a lot of meaning unless you want to count the number of dragging actions by example.

For the screenshots: what did you expect after the correct dragging of red 1 to blue 5? The result would be visible in the Snapping setup for the drop target 5. Can you post a screenshot of that setup?