Ipad mini Smart Cover doesn't work

What happened( problem before): At first when at first when I first got my ipad mini there was no option for smart cover lock/unlock, nor does the sleep/wake button work(there was only the restrictions option). I also wasn't able to use the button while taking photos.However, I could turn my ipad mini on and off. Even when I attached the smart over it wouldn't work, no matter how much I aligned the smart over. Then I accidentally dropped my ipad mini (around 40cm from the ground)and the option showed up and my ipad could screen lock using both the smart cover and sleep/wake button.

Problem now: Then after reading online with my ipad placed horizontally,my ipad suddenly screen locked, my sleep/wake button couldn't work. (Save for turning the ipad mini off). I turned the Smart Cover option off and the sleep/wake button could work. Yet, when I turned the option on again the ipad mini didn't screen locked when I closed the ipad mini with the Smart Cover. The sleep/wake button doesn't work as well.

I tried rebooting and it didn't solve the problem. Please don't tell me I need to do a system restore. I tried aligning my Smart Cover and nothing changed as well.

I apologize for the lengthy description.

I hope someone can give me some advice or solutions other than system restore.