Steps to regenerate:
1) Go to Content -> Survey
2) Find any survey and go to detail page.
3) Now go to "Questions" page of that survey.
4) Go to "Create New Question" section. Select a Survey Question Category Id and other necessary detail and click on Create button
5) Question successfully gets created but the list of questions from the selected "Survey Question Category Id" appears to apply to survey.
There is a separate section to apply questions from category. So IMO question from category should only come when we submit form to apply question from any category not when creating a question or editing any question.