Notification bars freeze and unresponsive touchscreen

Hi guys, so i just purchased an iphone 7+ a few weeks ago and accidentally updated it into ios 11.02 this morning . After that I was playing 'Bully' game like what i usually do and got a notification from whatsapp, i tried to open it and it just stuck there, i can't swipe down or swipe up the notification.

It seems like the one that didn't working is my touchscreen since it's unresponsive, it's like I can't touch anything at all, but my home button is great actually, when i click the home button it shows me Bully game's still running on the background apps but i can't close it down. I can still hear my instagram notif sounds and the only thing I could do is to hard reset my iPhone, it works fine after that. Is this a bug from ios 11.02? Any solution if this happens again?

Thanks in advance.

P.s i can ss my lock screen at that moment so i will attach it here.