Why didn't MX3 Unicom receive the short message just now?

First of all, please check whether the number of the SMS center is set, and also check whether the SMS setting has the function of receiving SMS and is turned on. Then you can send yourself a short message and see if you can receive it. I suggest you put your mobile phone card in another mobile phone to receive short messages. If the cell phone signal is good, you can send text messages normally, but you can't receive them. It may be a problem with the cell phone terminal. It won't work if you put it in another mobile phone, and the SMS settings are fine. Maybe it's the mobile phone card.