ListDrawerSettings(CustomAddFunction = "...") doesn't work properly when selecting multiple objects.

[Lyrcaxis]

When you select multiple assets and press the + button that calls the CustomAddFunction, it only procs for 1 object.

‌

public class MyClass : SerializedMonoBehaviour {
    [ListDrawerSettings(CustomAddFunction = "AddNew")]
    public List<string> stringList = new List<string>();

    void AddNew() => stringList.Add(@"o/");
}

‌

Using 2019.3.0b8 in Windows 10, Odin 2.1.8 and Editor only mode disabled.