I’m about to be on month 6 of Accutane and had clear skin thru the first 3-4 months, but my acne has come back, is this normal?

As a teenager, I had severe breakouts and went on Accutane with success. Seven years later, occasional breakouts became more severe and I went back on Accutane. Initially, my skin cleared up, but around the fourth month I started developing cystic acne again. My mom has also struggled with acne and has taken Accutane twice with mixed results. The first time it went well for her, but the second time she saw no results. Is this a normal course of events during treatment? Male 145 lbs 80mg / day