I don't think any SIM should be selected by default unless the user has set it to be the default.
One improvement would be rather than a "No SIM card selected" popup, it should offer you the choice, eg: a popup with two buttons, one to use SIM 1 and another to use SIM 2.
I don't think any SIM should be selected by default unless the user has set it to be the default.
One improvement would be rather than a "No SIM card selected" popup, it should offer you the choice, eg: a popup with two buttons, one to use SIM 1 and another to use SIM 2.