audio control fails with ibooks after a while
When I'm using iBooks to listen to an audiobook, I can pause and unpause using the headphone buttons.
But after some time (say, an hour or two), it no longer works. It seems like the app has been suspended, perhaps. To restore control, I have to manually unlock and launch iBooks. Then it starts working again.
Happens on my old 6+ and on my new X.
iPhone X, iOS 11.2.6