i have updated to new software ios 11.3.1 After that i noticed my ibooks app is not working properly.

Hi. i have updated to new software ios 11.3.1 After that i noticed my ibooks app is not working properly. The app is not showing proper sign inside ibooks like categories etc etc. Also books cover not showing properly, only red of black cover with book name only thats it. I deleted app and download again but result is the same. Also i restart my iphone several time but in vane. Some one plz help me as apple support is nkt responding from my area and i m v worries bc i used it v often. plz reply asap. Many thanks