Nasal graft visible? (Photo)

a year ago i had a revision rhino due to droopy nose and hanging columella , initially i developed a skin necrosis in the initial surgery so the new surgeon did not want to do anything with the tip, only closed rhino with septal graft and columella reduction, at 6 weeks op i felt a hard projection supra tip, since then it has been visible in certain light creating unnatural nose tip, i went to the surgeon but he did not give me answers on why this developed, so any idea why this happened? thank