When a Survey123 survey is published, the Platform creates a form item that the Survey123 app downloads and the feature layer that contains the data submitted from the survey. During the publishing process you are warned that once a survey is published, it cannot be changed. This is because feature layers are generated during publication, and editing of existing feature layers can be complex or, in some cases, impossible. However, despite these warnings, it’s possible to make limited edits to a survey and republish it without deleting the feature layer and the data stored in it. The table on the following page lists the changes you can make to a published survey that do not cause loss of data.
Caution:
Once a survey created with the Survey123 web designer is modified in Survey123 Connect, you can no longer edit the survey in the web designer.