Hi @hawala,
thank you for the examples. I found that the external task is marked as “Asynchronous before”, which causes the issue. This is not needed, as en external task is a wait state/transaction boundary/save point.
If you remove the checkmark, your test should run (I tested with my own test).
As an alternative, you can execute the job explicitly and afterwards assert for the external task characteristics.
Hope this helps, Ingo