What happens to my data when I edit an active survey

The behavior when you edit a live survey depends on how exactly you edit it. If you edit an existing response in a live survey, it should change how that response is coded for anyone who selected it previously... So for example, if I have the following response choices in my question:

• Apples


• Bananas


• Chocolates

If I edit "Apples" to "Apples are my favorite," after responses have been collected, then anyone who previously selected "Apples" will now be reported as "Apples are my favorite." This is mostly useful for when you need to make minor edits to spelling or punctuation - editing a response does not invalidate previous responses, it simply updates them. BUT you will run into issues if you substantially change a response during editing... Like if you changed "Apples" to "Peanut butter," then everybody who said "Apples" will now look like they said "Peanut butter."
If your user completely deleted the response "Apples" and added an entirely new response, then all the data for people who previously selected "Apples" would be gone, and would not be replaced by the new response that was added.
Here's a link to Qualtrics' help article on this topic: https://www.qualtrics.com/support/survey-platform/survey-module/testing-and-editing-an-active-survey/#EditingAnActiveSurvey
To my knowledge, the data in the Data & Analysis tab should match the data that gets exported to Excel. I'm not really sure why it wouldn't match there for you.