### 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)

void _resource_changed(const Ref<Resource> &p_resource);
	void _viewport_selected(const NodePath &p_path);
	void _sub_inspector_property_keyed(const String &p_property, const Variant &p_value, bool p_advance);
	void _sub_inspector_resource_selected(const Ref<Resource> &p_resource, const String &p_property);
	void _sub_inspector_object_id_selected(int p_id);
	void _open_editor_pressed();
	void _update_property_bg();
	void _update_preferred_shader();
protected:
	virtual void _set_read_only(bool p_read_only) override;
	void _notification(int p_what);
public:
	virtual void update_property() override;
	void setup(Object *p_object, const String &p_path, const String &p_base_type);
	void collapse_all_folding() override;
	void expand_all_folding() override;
	void expand_revertable() override;
	void set_use_sub_inspector(bool p_enable);
	void fold_resource();
	EditorPropertyResource();
};
class EditorInspectorDefaultPlugin : public EditorInspectorPlugin {
	GDCLASS(EditorInspectorDefaultPlugin, EditorInspectorPlugin);
public:
	virtual bool can_handle(Object *p_object) override;
	virtual bool parse_property(Object *p_object, const Variant::Type p_type, const String &p_path, const PropertyHint p_hint, const String &p_hint_text, const BitField<PropertyUsageFlags> p_usage, const bool p_wide = false) override;
	static EditorProperty *get_editor_for_property(Object *p_object, const Variant::Type p_type, const String &p_path, const PropertyHint p_hint, const String &p_hint_text, const BitField<PropertyUsageFlags> p_usage, const bool p_wide = false);
};
#endif