It had nothing to do with Trump or the election. The New York field office found classified and special access program email and when they informed HQ the case was taken away from them. When they asked for a status report nothing had happened as HQ were sitting on the case, so they were forced into reopening the investigation. It was a national security issue, as these emails were being accessed by a number of foreign countries. It was just people doing their jobs, nobody was seeking to damage any candidate.