Process instance does not become Completed state even though all nodes in the instance are completed.

For a process definition like below,

• Start node --> REST Service Task node (with "is Async" flag enabled) --> End node

when we do the following steps

1. Start a process.
2. RuntimeException occurs in the REST Service Task node above due to the destination REST server is not running.
3. Get rid of the problem situation by starting the destination REST server, and then trigger the REST Service Task using Trigger button.

the process instance does not become Completed state (still be Active state) even though all the nodes in the process instance are completed. At this time, Instance State of the process instance should become Completed.