Is septoplasty required twice?

In general a septoplasty should not need to be performed twice unless it was incompletely done. Occasionally the septum can change over time. A trauma to the nose could also lead the septum becoming deviated again. Other causes of persistent nasal obstruction include: untreated nasal allergies, inferior turbinate hypertrophy, and nasal valve collapse. Nasal valve collapse can worsen with time as the cartilages weaken with age. It is a very common source of persistent nasal obstruction after septoplasty. You should seek guidance from a surgeon who specializes in functional rhinoplasty to see what the exact cause of your nasal obstruction. 

 Nasal obstruction can be caused a  Variety of issues such as a deviated septum, turbinate hypertrophy, chronic sinusitis, a nasal fracture, valve collapse, vestibular stenosis, and allergies. Each one of these are treated differently  with either medications or surgery. It is best to seek out in person consultation/ examination with an ENT/ facial plastic surgeon to determine the cause of the obstruction.

Difficult to say if you need a second operation on the septum.  A consultation will determine what anatomically is going on and what might need to be done about it.  There are many reasons for your symptoms and problems with the septum is just one of them.