Known issue is under investigation (Score 1)

I used to work for apple and this is a known issue. They used to claim it was a software problem and to keep updating the iOS, although 1 major and more than 10 minor updates later the problem has not been fixed. According to apple engineets they have been invetigating this problem for almost 1 year now. For the phones that exhibit these symptoms most ( over 90% of the phones I have seen) pass the apple battery diagnostic test. Either: 1. Apple engineers do not know what is causing the problem 2. They know. As they have not offered ANY solution except updating the iOS, and I have not heard of any data regarding bad manufacturing batches they may genuinly not know what is causing the problem or how to fix it. They may end up issuing a recall for phones with this issues if China complain enough. Similair to the iPhone 5 home button problem. Almost all Asians are paranoid about home buttons now and use Assistive Touch or the rubber home button things.