We have a SPO environment and I'm creating a workflow in SPD 2013. When creating a 2013 custom workflow with a task assigned to a user, the email with the task notification does not include the "Open This Task" button. It only includes a link to the workflow task list "display" view. But the 2010 workflows successfully send the button with the task notification email. What's going on here? How do I get the "Open This Task" button to show in 2013 task email notifications?
There are differences between Workflow 2010 and 2013, you can change the Send Task Behaviour and add link to the email.
Hope it helps!