Drag&Drop - it can't be done

The output made in SL360 has a problem with drag&drop excercises. The dragged pieces do not stay put where they are dragged and the excercise cannot be done – the OK buton does not appear and all you can do is close the module halfway. Therefore, the whole module is not completed and stays on the to-do list.

We tested 2 outputs of the same module (2 languages) that were made in SL360, and one of them got passed and the other didn’t. Apparently the error can randomly occur or not, as one of the modules was completed, whilst the other wasn’t.