I'm using the Plex app on an iPad Pro with iOS 10.3. Things work well EXCEPT the sync content process stops when the iPad screen automatically locks. You need to either disable the Screen Lock altogether in IOS settings OR keep touching the screen to keep the device from locking. Is this intended behavior? Given that content syncs take some time, it would be nice if you could set it going and not have to worry it.
Seems like there should be some way to keep the device from locking until the sync process is complete. They clearly know how to do this -- they keep it from locking when you are watching content.