我有一个计划按小时运行的任务，但是没有被触发。当我看着Task Instance Details时说：
All dependencies are met but the task instance is not running. In most cases this just means that the task will probably be scheduled soon unless:
- The scheduler is down or under heavy load
- The following configuration values may be limiting the number of queueable processes: parallelism, dag_concurrency, max_active_dag_runs_per_dag, non_pooled_task_slot_count
- This task instance already ran and had its state changed manually (e.g. cleared in the UI)
If this task instance does not start soon please contact your Airflow administrator for assistance.
如果我清除了UI中的任务，则可以通过终端执行该任务，但是在计划时它不会运行。
为什么每次运行后都必须手动清除它？