Normal, habit is good, iPhone data line aging common disease, used for a long time are a little. I am now using the green link, there is a 6s and a 7,6 s for daily use, 7 to play games, tried a few times, is also this problem, but not as serious as yours, mine is inserted into a few seconds can not be filled, and then you change the direction of back and forth insert a few times can be charged, the original one also has this problem, more in the direction of plug and insert a few times is good, It's nothing.