Cystic acne 2.5 months into Accutane?

I did not have a purge (or any significant one to speak of) and my acne has been clearing quite well. My cheeks which were my problem area are mostly clear.

Lately I have been getting deep HUGE cystic acne that’s not super visible but can definitely be felt. It’s mostly on my chin and around my mouth.

Is this a normal thing? Late purge? The accutane has gotten surface level stuff and is now working deeper?