The Qualtrics support page says “Edits should not be made to questions created in the Follow-up Details once they have been published”, but it also has a section that outlines “How Follow-Up Questions Edits Affect Ticket Reporting”:
HOW FOLLOW-UP QUESTIONS EDITS AFFECT TICKET REPORTING
When you edit your ticket follow-up questions, you may impact your ticket reporting dataset. Continue reading about how different edits will impact your dataset.
Adding / Deleting Answer Choices
This change does not have negative implications for ticket reporting. None of the existing responses will be impacted. Responses after the addition / deletion will simply be in the new range of possible answers.
Editing Question Text
This change impacts your ticket reporting dataset. Rephrasing a follow-up question is the equivalent of creating a new one. None of the existing responses will be affected; however the new phrasing will need to be mapped as a new field in ticket reporting as it is considered a new field. All future responses to the new phrasing will appear in the newly mapped field, and none will go to the old field.
Deleting a Follow-Up Question
This does not have negative implications for ticket reporting. None of the existing responses will be impacted. After the deletion, no new responses can be collected for the old field.
Here is the support article for reference: https://www.qualtrics.com/support/survey-platform/actions-module/ticketing/tickets-task/#FollowUpDetails