I got a new Verizon iPhone SE 64gb. When I put my postpaid AT&T SIM card inside, it will only show AT&T 3G. No HSPA+ or 4G. If I plug that same SIM card into my other Verizon phone, a Samsung Galaxy S7 edge, it will have no problem picking up HSPA+ immediately.(in fact, it never even bothers connecing to 3G) Not 4G, since the Samsung doesn't have the 4G bands for AT&T. Are there some settings that I need to change or add, in order for the Verizon iPhone to pick up AT&T's HSPA+ and/or 4G bands? In settings, there's an option for 4G. I've tried turning it on and off. No difference. Thanks!