This situation has nothing to do with your practice. The abdominal muscle segmentation in our common sense is actually a wrong concept. The abdominal muscles we are talking about are rectus abdominis. There are only two rectus abdominis muscles on the left and right sides. The reason for the "block" is that there are several "tendons" on each rectus abdominis (that is, the horizontal lines drawn on your image) to divide the rectus abdominis into several muscle abdomens. But this tendon is determined by genes and cannot be changed the day after tomorrow. This is the case with many bodybuilders. If they can be changed by external forces, will they let it go?