After reinstalling the SIM card, the Huawei children's watch cannot be located and sent to the parent-child chat. You can try the following methods to solve the problem: 1. Check if the watch's positioning function has been turned off. If it had been turned off, he would turn on the location function again and try to send a parent-child chat. 2. Check if the watch has an internet connection. If the watch does not have an internet connection, the parent-child chat cannot be sent. Make sure your watch is connected to the internet and try to restart it. 3. Check if the watch has set the message ban. If the watch forbids sending messages, the parent-child chat cannot be sent. Please check the settings of your watch and make sure that it is not set to prevent sending messages. 4. Try to use another phone or computer to send a parent-child chat. If the watch uses the same SIM card, you may need to use other devices to send messages. If none of the above methods can solve the problem, please consider contacting the watch's technical support for help.