A minor annoyance was discovered by some iPhone 7 users while using the bundled Lightning EarPods with the device. Turns out, if there is no audio playing on them for over five minutes, the controls stop working unless you unplug and plug the headset back in. Business Insider spoke to Apple about this issue and the company confirmed it will be fixed in the next software update. The issue seems likely to be a USB power delivery feature of some sort, where the USB controller is designed to cut power to connected devices if there is no activity for a set amount of time (five minutes, in...
Source: http://www.gsmarena.com/apple_working_on_lightning_earpods_control_issue-news-20615.php