Completed task wont trigger next step?

So I set up a campaign with a fill-up web form and added a task sequence to approve or disapprove applications.
When I approved the application and marked the task completed in contact information in IS, It doesn’t trigger task completion on the campaign which is supposed to go to the next sequence. Is this a bug? Can anyone help me with this?

this is the task completed:

It’s supposed to take the contact into a sequence that adds tags and send them confirmation email. but it’s not doing so.