You can't receive messages if you change your mobile phone card.

Mobile phone setting problems, SMS center problems, etc.

1, phone setting problem: phone setting error may cause mobile phone card 1 to receive short messages, but card 2 can receive them. The solution to this problem is to check the mobile phone settings to ensure that the SMS reception settings are correct.

2. Short message center problem: It may be that there is a fault or error in the short message center, so that 1 card can't receive short messages, but 2 cards can. The solution to this problem is to contact the customer service department of the mobile phone operator, ask if there is any problem in the SMS center and ask for help.