UserDefaults is not saving data after suddenly closing device

Question

I am logging app and loading home page all task working properly. After login I save user data in UserDefaults. But if I suddenly close Apple TV then I am getting UserDefaults data as nil.

I am using this:

UserDefaults.standard.set(true, forKey: "isLogin")
UserDefaults.standard.synchronize()

let apiToken = UserDefaults.standard.value(forKey: "isLogin") as ? Bool