Sry for the late reply! I've checked the chapters and didn't seem to find the problem. However, I'm guessing that you're reading Jamming Scans & co. translation uploaded by vigorousjammer. They seem to order volume 3 contents by 10a, 10b, and so on (considering volume 3 is indeed 1 giant chapter). Whereas I divided them into chapter 10, 11, and so on until 14.