Column actions on task form layout editor are displayed below the task pop

If on a task node, you create a task form with two columns it is not possible to delete the first column, because the actions list to do so is displayed behind the task pop up, and is thus not visible.
To reproduce:

• create a workflow or edit an existing one
• edit a task node
• create a form with two columns
• try to click on the header actions of the first one ---> nothing appears