Questions missing when I preview form

Billy Ivey I've got a form will 11 questions (not branched) but on preview and completion it only allows the completion of 6 questions. Questions 5+ are in a separate section but no idea why the questions don't appear from 7 onwards? I've tried deleting questions and re-adding; changing required status and removing - none of these make a difference. I've had this issue for a number of months and very disappointed that as a Microsoft software service, such a simple function really shouldn't be this difficult.