Yes, when you add a new question to a live survey, it will only be visible to future respondents. For responses collected prior to adding the question, no data will be recorded for it. However, you can manually update these past responses by:

1. Navigating to the Response Viewer.

2. Opening each completed response individually.

3. Clicking "Edit" and entering the answer for the new question.

This lets you backfill the data, but the updates need to be done one response at a time.

Note: Avoid inserting a new question in the middle of the survey. Instead, add it after the last question to maintain the original survey flow and preserve the integrity of previously collected data.

Here is a helpfile for your reference on how to edit a response - https://www.questionpro.com/help/response-viewer.html