Oppo dual card does not receive SMS by default.

Solution steps of oppo dual card not receiving SMS by default:

1. Make sure the phone has been updated to the latest software version, which may fix some common problems.

2. Check the SMS settings to ensure that the default SIM card for receiving SMS is set correctly. Find the option of "SIM card and mobile network" in the settings, and select the appropriate SIM card under SMS settings.

3. Try to delete and reinsert the SIM card. Sometimes, incorrect installation or poor contact of the SIM card may cause the dual-card function to fail to work properly.

4. Restart the phone. Sometimes, restarting can clear some problems and resume normal operation.

5. If the above steps fail to solve the problem, please contact the customer support of Oppo mobile phone for further help and support.