@lluo100The questions are missing because of branching. To fix it, select any question or at the right side of the section click (...) and choose "Add branching". On each question or at end of each section you should see Go to "Next". If you see any other "section" or "End of the form" in Go to field, all questions between the selection will be skipped in the preview(user View). Hope it helps someone who is still looking for a solution.