I couldn't find a direct answer to your question in the Prefect knowledge base. However, there could be several reasons why a task might be stuck in a 'Retrying' status even though the log says 'Completed()'.
Here are a few possibilities:
1. There might be an issue with the task's retry mechanism. If the task is set to retry after a certain condition is met, it might be stuck in a loop of retrying even after it has completed its operation.
2. The task's status might not be updating correctly due to a bug or an issue with the Prefect Cloud.
3. There might be a discrepancy between the task's actual status and what's being displayed in the logs or the UI.
If you're still facing this issue, I would recommend reaching out to the Prefect community or support for more specific guidance.