Contacts from submitted forms are not added to the list
You can follow these steps in order to troubleshoot why contacts are not added to the form. How are contacts meant to be added to the list?
Make sure to go into your List Settings and see if actions are correctly set
Make sure that filters in List Settings are correctly set
Sometimes, option like When all or When any are overlooked. See if that option is set correctly
Is your form active and appears on landing page
Does it have required fields
Did you used Visual Workflows to add people to the list, if you did, check triggers and filters there as well
PEOPLE HAVE STARTED filling out my form, but I forgot to make a list
All you need to do now is create a Rules-based list
Simple navigate to the Content > Forms
Select your form
Click on Submissions (and here you can see all people who filled in your form)
You can then add each person to your list
Then you can click on each person and add them to the list by clicking on green Add to button.
Select option Add to List and select list of your choice.