If you accidentally clicked on the 'overwrite published' button inside of survey designer or if you clicked it because you've done some changes to the design version your export could be affected because technically you created a new "reset" version of the survey.
In this case, you can click on the Actions tab inside of the survey designer and click on the "Links and exports all versions". Scroll down and you will be able to find all versions of the survey and all exports.
Note - "Reset" means the new published version doesn't have any data yet such as previous completes, survey quotas, etc.