400638 1030 should be the number from "Shenzhen Gitzo Today Service Co., Ltd.", but the questioner himself is convinced that there is no intersection with this company in Shenzhen and WeChat online, and there is no need to investigate and correct it. Because with the development of the Internet, fraud, harassment, advertisements and intermediary phone calls can be fabricated with various software and displayed on your mobile phone. As long as you can't call back, most of them are similar scams, harassment, advertisements and intermediary calls!
I have had many similar personal experiences: after living in a military hotel with my comrades-in-arms, in addition to using this software, the distance between two single beds in a standard room, my comrades-in-arms can call my smart phone at will, and even my mobile phone receives a call showing my mobile phone number.