Why can't hellotalk be read back by Koreans?

Network delay. Hellotalk is a software developed by Shenzhen Xinhui Technology Co., Ltd., which was established on 20 18. According to official website, Shenzhen Xinhui Technology Co., Ltd., the original intention of the company to develop this software is to let Chinese people know about life abroad. Chat software shows that users can't read back from China to South Korea due to network delay, so users need to wait patiently. The company's business scope includes computer software and network technology development; Technology development, technical services, technical consultation and technology transfer in the fields of education and science and technology.