When the SIM card of the mobile phone is changed to another mobile phone, why are all the text messages originally stored in the card missing? How to solve the problem?

SMS messages can be saved to the sim card or the phone itself. You can use the backup function to back up to the SD card.

However, there is an upper limit for the storage of text messages on a mobile phone card, usually about 20 messages. The excess will be automatically stored in the phone, and will disappear if the phone is flashed...

Suggestion It is a regular backup, you can use YY backup or mobile assistant.

If you have backed up before, you can try to restore it. The most common backup format for text messages is “.vmg”