First, you love this phone for its battery life than screen size but you want to know about its problem. Problem-based on where did you buy it.
1.if you buy from retail shops: you’ll not get any problems with the phone chance of your phone problems is 4/5.
2.if you buy from online: you’ll face that problem in 3-4 months like automatically vibrate alarm not working screen touch problems etc.
That all above problems will face you if you took your phone into vibration mode or if you swipe your phone screen with wet clothing.