Attached is a simple test case that
1) Deploys process definition with two nodes
2) Starts 20 executor threads
2) Starts the process instance that will asynchronously execute action on the second node
4) The second node writes a record to the database

The test case needs to be executed multiple times to see the incorrect behaviour.
This is an example of run output
Isol 8
Action 1
Success 0
Failure 0
Action 2
Action 2 1
Action 2
Action 2 1
Action 2
Action 2 1
Action 2
Action 2 1
Action 2
Action 2 1
Action 2
Action 2 1
Action 2
Action 2
Action 2 1
Action 2 1
Action 2
Action 2 1

Explanation of the outcome
9 job executors successfully executed the node action (same job) including database operation. All database operations were comitted (9 new records were created)