I’m facing issue with simcom module. The problem is if we send msg it will be black there will be no text or anything it will be just blank. The same code will work fine on BSNL. Other network yet to test. And tested with different simcom module like sim800l , sim800, sim800c etc, on Airtel 4g new sim it will be blank. But we can receive messages properly. Is anyone else faced same issue ?
Check if you are sending any binary characters. Some SIM network wont allow specific non-ASCII characters in SMS.