Samples are successfully being sent to Sandboxing and can be seen, and tasks can be manually created and run. However, tasks are not seen to be created/run automatically.
The CAS appliance is trying to submit to default profile, and it's probably indicating it doesn't exist. We can fix that by specifying a profile on the other page. Please see the snippet below.
You will need to click the "Add" button, to specify the profile, to have the profile automatically run the tasks.