ObserveSingleEvent does not work good - ios

Question

My realtime database looks like this:
It contains only 1 child as you can see. I had 4 more children in RunningGames a few minutes before. I deleted them in the browser. When now calling this:
private lazy var runningGamesRef: FIRDatabaseReference = FIRDatabase.database().reference().child("RunningGames")
self.runningGamesRef.observeSingleEvent(of: .value, with: { (snapshot) -> Void in
for gameSnap in snapshot.children {
let id = (gameSnap as! FIRDataSnapshot).key
print(id)
}
})
It still prints those games I deleted in the browser. Calling runningGameRef!.removeValues() in my app does deletes it in the browser and on the iPhone (the print(id) is fixed). I have this error on multiple observeSingleEvent functions on different children, not only children of RunningGames. What would cause this annoying error?
Some children in RunningGames also have children, but they do auto remove themselves in the app. However, these values are also still visible when calling observeSingleEvent.

Answer 1

It's probably your local cache that's still holding the outdated info. This often happens when you're manipulating data from multiple sources.
I would try using observe instead of observeSingleEvent. I know it's a bit odd (and not really what you want if you only want to load the data once) but that should keep your info up to date.
Maybe by doing this you could fetch the info just once.
var handle: UInt = 0
handle = ref.observe(.value, with: { snapshot in
for gameSnap in snapshot.children {
let id = (gameSnap as! FIRDataSnapshot).key
print(id)
}
ref.removeObserver(withHandle: handle)
})
Source of the code (Frank van Puffelen)