This phone was used on Google Fi for 2 months, is unlocked and compatible with the new Boost EN. I checked the IMEI and it said it was active on Sprint. I called and, after checking, the CS rep told me it was fine, not connected to any account, just get a SIM card. I did, but when I tried to swap, it said I couldn't. I called again, the CS rep checked, then told me he couldn't swap it either, and to contact Google. It is unlocked, was reset to factory, the original owner's Google account was deleted and I registered mine so it should be good to go. I don't know what else to do, help/advice would be appreciated.