For some reason the actual Task in the process is not being completed. If you see the same Task ID then you are probably still looking at the same actual Task because if a new Task was created, it would still get a new ID incrementing in value. What happens when you select the green check mark in the Task card in Workspace (rather than complete from the form view). If this works then perhaps there is something wrong with the submit button on your form. Also, what version of Reader are you using?