“Is this phone 'region-locked', meaning it only works in N&S America? I've read that Samsung 'region locks' phones; in this case, the phone (as I've read elsewhere) may be considered 'unlocked' BUT is still 'region-locked', having something to do with the SIM card, only allowing use w/i N&S America. Other articles state that IF the phone is used for at least 5 minutes w/i the region it's locked, that lock is undone and e.g. one can now get a SIM card for e.g. the UK and use the phone there. (My current old 2G phone worked w/i the UK without even needing to change the SIM - would this phone work 'native' w/o a SIM change if the network freqs are compatible?)”