#iphone notifications tip. For those who are wondering why their notifications on the lock screen say stack collapsed, I have solved this mystery. If you go to settings then notifications, toward the top of the screen you will hear display as. If you select list and not stack which is the default, your notifications will appear just like they did before the smart stack was introduced in iOS. This has been annoying me for a few days and I finally worked it out. I hope it helps others here.