I'm not really sure where this question is belong to, so I'm posting it here and in "Android Q&A" as well, hopefully to get a decent answer...
I've just bought an Android phone (JIAYU F1 - link here), and it's really great.
Thing is, I have special SIM from my carrier, that allows me to use only certain models of phones, and not others.
I moved the SIM from the old phone to the new one - and for the first 10 second - it was great.
I could dial numbers, and recive call from other phones. BUT - after like 10 sec's or so - I saw the words "USSD sent" on the screen, some blank message appears, and since I clicked OK (no other choice...) - I couldn't make and receive any calls.
My guess is that this "USSD message" is responsible for the whole mess, reporting to my carrier which phone model using the SIM right now.
This is why I want to find a way to prevent it to be sent to my carrier.
I'll be thankful if you can help find this way...
Thanks in advance.