If a question has responses, you can edit the question text and sub text and those will save. To edit answer options and other things, you have to "uncheck" the box as shown in the below screenshot. This warning indicates that if you change answer options, the prior answers that no longer match will be deleted. So make sure you don't have to change answer options after the survey launches.
If you only have testing responses, then clear the responses. The other option is to over-ride and uncheck the warning box to save the changes (which will delete the resposnes for that one question) upon save.
