WaitForOrchestrationAsync returns null for orchestration in Completed status

We have recently encountered an increasing number of cases where the `WaitForOrchestrationAsync` method returns null for an orchestration instance that is already in the `Completed` status. This issue has been observed in both the 2.6.0 and 2.13.0 versions of the `Microsoft.Azure.DurableTask.Core package`. While this problem used to occur rarely in the past, it has become more frequent over the past month.

This issue is particularly critical for us because we have a recurring orchestration for capacity management work in our service. When the `WaitForOrchestrationAsync` API returns null, it causes the orchestration to hang, resulting in serious production issues on our end.

We would greatly appreciate your assistance in investigating this matter and determining the potential causes. Additionally, we would like to know if there is a stable version of the package that we should upgrade to in order to mitigate this issue. If there are any best practices or recommended approaches for gracefully handling this situation, please kindly provide your suggestions.

If you require any further information or details from our end, please do not hesitate to let us know.