Hi @Lillian_Kim and welcome to the Forum!
I’m sorry to hear you are running into this issue. When you duplicate a task, depending on how much subtasks you have and how much data these subtasks contain, the duplication might not happen instantly and can take some extra time.
Could you please confirm if you can see now all the subtasks duplicated?
If not, I would recommend to reach out to our support team following these steps and providing them with 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)
They’ll be able to take a closer look into this for you.
Please let me know if there is anything else I can help you with!