Have subtasks remain with the parent task when dragged to individual days

When you have a task scheduled for this week and the task has subtasks. And you show subtasks and quickly move a subtask to an individual day the subtask gets removed from the parent task. Only if you go inside the subtask and schedule it it will remain with the parent task. In the week, monthly and yearly view it would more quick to be able to drag the subtask to the correct day.