When updating a form, you need to create a new revision of the form. This allows for an archive of the form, when audited you are able to see what version of the form was submitted. Revisions also allow you to make alterations ahead of time, but not publish them until more information is needed to be gathered.
Creating a New Revisions
Click into the Form you want to Revise.
Select the Revisions tab
Click into the current published Revision
Select New Revision
This will create a new draft with all the elements to edit
Save once you're happy with the form, then you'll need to make it active.
Making Forms Active
You may have as many revisions as you like, but the only revision that can be seen from the field is the one that is published and marked as active. A form can only have one active revision at any given time.
Click into the form you want to make active
Select the revisions tab up the top
Choose the revision you want to make active
Make sure you've published, then press Activate. this will automatically save
