VAF sequential task queue was added but not starting and running

Hi, I have created a VAF with BeforeCheckInChangesFinalize event handler and deploy it to a cloud vault.

The VAF will check the status property of every documents and update the status, the update of document status will be perform in batches (task queues), 100 documents per batch/queue.

Currently, I faced an issue that the task was added but will not start and run in the background. May I know what could be the root cause of this issue and how could I solve it?