iPhone 6 touch screen issues

im a new iPhone user..my phone was ok at 1st. After I updated it to iOS 9 I found my touch screen a little less responsive & sensitive..after updating it again to ios9 the newer version 9.01 my touch screen jus froze....nothing responded to my touch apart from the assessibility floating around at the side. I have to do a hard restart for it to be ok again..please advice if this is a normal issue happening with iPhones???or is there something wrong with the iOS 9?? Please advice...