K1526593509552 , via OnePlus 7 , Sep 20, 2021 : I recently shifted to USA. I am using indian mobile which is OnePlus 7. I bought new sim card AT&T but it is not working in OnePlus 7 2019. I checked with the customer support they told me my device is not compatible but the same sim when kept in my friend mobile which realme 2018 device it's working very well. I don't what is wrong in my device.