Unable to answer call as there is no call interface when the phone is ringing
I am using iphone 6s with OS 11.4.1. Recently my phone acted strangely as there are a number of incompleted apps appeared on my home screen i.e. demoapp, data activation, checkerboard etc. In addition, i am also unable to pickup incoming call although i can hear the phone is ringing - there is no call interface where i can slide to pick up the call.