This is the explanation of Reactivation lock by Samsung. Reactivation lock lets you use your Samsung account to prevent others from activating your device if it’s ever lost or stolen. With Reactivation lock turned on, you will be required to enter your Samsung account credentials prior to performing a factory reset on the device, so your Samsung account login should be something you can easily remember. So what i’m asking here is, will the Reactivation Lock remain functional even after the phone is flashed or installed with custom ROM?