I created a workflow some time ago that ran as expected. 

The workflow creates tasks of content type 'Nintex Workflow Multi Outcome Task'.

The workflow also created To do's. I remember that I changed the column order for some of the to do's.

The problem is that now, the tasks that are created with a Flexi task, don't show the Approve/ Reject radio button anymore. Instead, those tasks look like a to do (start date, due date, % complete, ...).

The old tasks that were used to approve also show the to do lay out. Like this:

How can I revert the task form back to the way it was?