What's wrong with SIM card not sending text messages?

Hello, according to the situation you described, I suggest that you can troubleshoot as follows:

If there is no signal or the signal is poor, you can go to a place with strong signal to test.

Case 2 is blacklisted by SMS, and it can only be used normally after going to the business hall to remove the blacklist.

After the above reasons are eliminated, it still cannot be used normally. You can click /qAHfS for feedback, and we will check and handle it as soon as possible.