Responses
yes, in the official kr it's written as S3 prologue if i'm not mistaken
i just checked kakao kr and yes, the first comeback episode was S3 prologue, updated a week before the scheduled comeback.
then a week later they uploaded ch 66, 67, and the most recent was ch 68.
I'm guessing that chapter 66 is a recap + season 2 preview, while the first chapter 67 is the actual chapter 66.