Is Yangzhong Jiangnan or Jiangbei?

Yangzhong is an island in the Yangtze River in Jiangsu Province, which is located in the south of the main channel of the Yangtze River and should belong to the south of the Yangtze River. The problem is that the dialect spoken by Yangzhong people is Jianghuai Mandarin. Jiangbei is a bloodline, and people who speak Jianghuai Mandarin are undoubtedly Jiangbei bloodline. Geographical Jiangbei and humanistic Jiangbei are the same concept, so Yangzhong is regarded as Jiangbei. On the other hand, Chongming Island in Shanghai is located in the north of the main channel of the Yangtze River, but Chongming people speak Wu dialect. According to textual research, Chongming people are descendants of ancient Jiangnan immigrants, so Chongming people have always been regarded as Jiangnan people.