Singleton call twice when I switch to another scene and return back

Question

I'm working on a Unity project where I have a Singleton class, XPmanager, which is responsible for managing XP data across multiple scenes. I'm using the DontDestroyOnLoad method to make sure the XPmanager instance is preserved when switching between scenes.

However, I've noticed that when I switch to another scene and then return back to the main scene, the Awake() method of my XPmanager is called twice, and the Instance IDs are different, indicating that a new instance is being created. This results in the loss of the XP data.

public class XPmanager : MonoBehaviour
{
    public static XPmanager singleton;

    // Other fields ...

    private void Awake()
    {
        if (singleton == null)
        {
            singleton = this;
            DontDestroyOnLoad(gameObject);
        }
        else
        {
            Destroy(gameObject);
        }

        // ...
    }

    // Other methods ...
}

I've checked that there's only one instance of the XPmanager in my project. Despite using DontDestroyOnLoad, the Awake() method is called again with a different Instance ID when I switch back to the main scene.

Why is this happening, and how can I ensure that only a single instance of the XPmanager is preserved across scene changes?

Answer 1

DontDestroyOnLoad only works for root GameObjects or components on root GameObjects.

I set all my singleton managers as children of an emptygameobject and doing so caused my problem.