I have integrated BlueMix push notifications into my iOS app, and I have verified that the app can receive notifications. However, after some period of time, the app stops receiving them.
When I query the registered device list via REST API at https://mobile.ng.bluemix.net/imfpush/v1/apps/xxxxxxxx-xxxx-xxxx-xxxx-xxxxxxxxxx/devices
the device IDs I expect to be there are now gone from the list. What happened to the devices? Do they become unregistered by some automated process? Is there something I can do from the app side to make sure these devices do not become unregistered?