Isn't Guangxi a big immigrant province?

No, according to official website of China Historical Research Institute, Guangxi was incorporated into Chinese territory after learning that Qin Shihuang's Kailing District had traveled south. The earliest Central Plains immigrants in Guangxi were Qin Jun soldiers who went south that year. During the period of Emperor Wu of the Han Dynasty, South Vietnam was destroyed, and since then, Guangxi has never been separated from the central government. From the end of the Eastern Han Dynasty to the Yongjia Rebellion, the population of the Central Plains began to cross the border on a large scale, and the number of Han people in Guangxi began to increase. Until the Tang Dynasty, Guangxi was still relatively wild and was the main place to exile prisoners. For example, Liu Zongyuan was exiled to Guangxi at that time.