### Godot version

4.0-rc6

### System information

Fedora 37, Mesa Intel ADL GT2

### Issue description

Code that works as expected at runtime fails with Nil references to (assigned) exported vars in the editor:

![tool_global_position_error](https://user-images.githubusercontent.com/364501/222031460-ffb1ecbd-5175-4a42-8470-25285ba5f821.png)


### Steps to reproduce

Try to access the `global_position` of a `Node3D` that's assigned to an exported var.

See that it works at runtime.

See that it errors in the editor with:

> Invalid get index 'global_position' (on base: 'Nil').

### Minimal reproduction project

[tool_test.zip](https://github.com/godotengine/godot/files/10856640/tool_test.zip)

GDCLASS(EditorPropertyLocale, EditorProperty);
	EditorLocaleDialog *dialog = nullptr;
	LineEdit *locale = nullptr;
	Button *locale_edit = nullptr;
	void _locale_selected(const String &p_locale);
	void _locale_pressed();
	void _locale_focus_exited();
protected:
	static void _bind_methods();
	void _notification(int p_what);
public:
	void setup(const String &p_hit_string);
	virtual void update_property() override;
	EditorPropertyLocale();
};
class EditorPropertyClassName : public EditorProperty {