Hi @Ashly_Cheang 
Welcome to the Forum!
Sorry to hear you are running into this issue. To investigate this, we would need access to some private info that can’t be shared publicly in the Forum. So I would recommend you to reach out to our support team who will be in a better position to assist you further. To contact Support, you just need to follow these steps. When you do, make sure to provide them the following information:
- URL of this thread so you don’t have to explain everything again
- URL of the initial task
- URL of the duplicated task (in which subtasks are missing)
I hope this helps Ashly! But please let me know if there is anything else I can help you with!