I bought the Galaxy S9 (Unlocked). I have boost SIM from another mobile and when I try to use that on this S9 then for the first few minutes it works. But sim is locked after that. when I try to swap the device online I get the error msg This device is not eligible to swap.
Hi there, @amirgc! SIM cards may not be shared between two devices. Each SIM card is assigned to a device and paired together. You may not simply pop a SIM card out of one device and use it immediately in another device. You will need a compatible SIM card for your unlocked device. You can get it using the eligibility checker here at https://activate.boostmobile.com/bring-your-phone.