What happened when the SMS prompt turned into a comma?

1. A third-party SMS software is installed in the mobile phone, resulting in system conflict.

2. The current area signal is weak or the cell phone signal is interrupted for a short time. Short message is text or digital information sent or received directly by users through mobile phones or other telecommunication terminals. The number of characters that users can send and receive SMS at a time is 160 English or numeric characters or 70 Chinese characters.