Why is it that when a mobile phone sends a text message, it clearly says something, but the other party can't receive anything, and there is a "white screen"

You shouldn't send text messages, should you? The decoding methods of mobile phones are different, such as domestic MediaTek products. Some domestic products will add their own music, while Nokia or Motorola, for example, will have a blank screen, so it depends on what you send. If it's words, you don't know.