When I have a business process with a human task which has 2+ potential owners, I cannot find the task in the Task List of Workbench even though I am logged as the user of one of the potential owners. Even though I added another filter to get tasks based on the process instance ID, nothing appeared.

To reproduce the issue:
1) Create a new business process with single human task
2) Configure the human task to have 2 potential owners (actors=ibek,john)
3) Build and Deploy the project
4) Start the process
5) Open Task View
6) See there is NO task which we could CLAIM and START

On KIE Server or Workbench there are NO exceptions.