1. For dual card settings, the default data is in card 1, then card 1 and card 2 are normal, but the default data is switched to card 2 and an error occurs.
As a result, only card 1 can be recognized, but card 2 cannot be recognize...
Is dual card normal?
Is the SIM card reading speed normal?
I used the following version before and found that reading the SIM is very slow, more than 5 minutes, and the signal is a bit poor.