I recently purchased an unlocked Galaxy S6 from B&H Photo and I have a prepaid account at T-Mobile. I know that updates for apps I have installed come from the Play Store but what about OS updates? The reason I ask is that two days ago I received notice of a major update to the OS (Fingerprint reader, etc) which was 259MB. I downloaded and installed it. Initially, the fingerprint reader seemed to be improved but the next day it stopped recognizing my fingerprint and my backup password. Thanks to help elsewhere on this site, I finally got into the phone and disabled the fingerprint reader but I was hoping to use SamsungPay at some point. Any thoughts?