Unity EditorWindow loses state if Scene view is maximized.

WindowStateIsLostWhenViewIsMaximized.cs

using UnityEditor;

public class WindowStateIsLostWhenViewIsMaximized : EditorWindow {
	
	[MenuItem("Window/Bugs/Window State Is Lost When View Is Maximized")]
	static void Open() {
		EditorWindow.GetWindow<WindowStateIsLostWhenViewIsMaximized>();
	}
	
	string _state;
	
	// Steps to reproduce:
	// 1. Open this window
	// 2. Type something in the text field
	// 3. Select the Scene view
	// 4. Press <SPACE> to maximize it
	// 5. Press <SPACE> to restore it
	// 6. Text field lost its state
	void OnGUI() {
		_state = EditorGUILayout.TextField(_state ?? "");
	}
	
}