### 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(EditorPropertyFlags, EditorProperty);
	VBoxContainer *vbox = nullptr;
	Vector<CheckBox *> flags;
	Vector<uint32_t> flag_values;
	void _flag_toggled(int p_index);
protected:
	virtual void _set_read_only(bool p_read_only) override;
	static void _bind_methods();
public:
	void setup(const Vector<String> &p_options);
	virtual void update_property() override;
	EditorPropertyFlags();
};
class EditorPropertyLayersGrid : public Control {
	GDCLASS(EditorPropertyLayersGrid, Control);
private:
	Vector<Rect2> flag_rects;
	Rect2 expand_rect;
	bool expand_hovered = false;
	bool expanded = false;
	int expansion_rows = 0;
	int hovered_index = -1;
	bool read_only = false;