After 2 days full use, I managed to lock myself out of brand new S7 Edge. Dealer is exchanging, but what did I do wrong? I don't want a repeat of this issue. Fingerprints stopped working and dot-to-dot pattern would not catch the middle dot. Dealer just said to return it, but I'm a bit nervous with not knowing the cause. The fingerprints went first, then dot pattern. I didn't add any non-Samsung apps - only apps offered on the phone itself. Was this a screen flaw or user error?