If your Survey Template uses Skip Logic, you should check the Skip Logic once you have reordered the questions as you might need to set some of the Skip Logic rules again now that the order of the questions has changed.
Steps
Use Drag & Drop to change the order of the questions - watch the walkthrough: https://www.loom.com/share/e5abcfa8f5434b45ada71331987b57f1
Scroll to the bottom and press Save