The card number of Xiaomi's mobile phone m 1 is different.

1. Two SIM cards of different operators: If two SIM cards of different operators are used at the same time, the phone number, SMS number and data service number on each card will be different.

2. Two SIM cards are of different types: if a 3G or 4G card and a 2G card are used at the same time, the card numbers will be different due to different network standards.

3. Poor card contact: If the SIM card is inserted incorrectly or has poor contact, the mobile phone may not be able to correctly identify the card number. You can try plugging and unplugging the card again to ensure that it is in full contact with the card slot.