I added a CalDav calendar to Thunderbird that is hosted on a Nextcloud instance. While the calendar view looks decent, the tasks view is completely bloated with old, already completed tasks, some even from 2023. I selected "open tasks" or "current tasks" (? German translation) from the menu on the left side. It's not that all of the tasks are misclassified: When I go to completed tasks, there are hundreds of (correctly) completed tasks listed, but still. Furthermore, the sub tasks of a main task are not grouped. Is this a known limitation or am I missing some configuration? In general, as of now, the task view is pretty unusable for me. Anything that I can do to help debugging this?