### 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)

#include "editor_properties_array_dict.h"
#include "core/input/input.h"
#include "core/io/marshalls.h"
#include "editor/editor_properties.h"
#include "editor/editor_properties_vector.h"
#include "editor/editor_scale.h"
#include "editor/editor_settings.h"
#include "editor/gui/editor_spin_slider.h"
#include "editor/inspector_dock.h"
#include "scene/gui/button.h"
#include "scene/resources/packed_scene.h"
bool EditorPropertyArrayObject::_set(const StringName &p_name, const Variant &p_value) {
	String name = p_name;
	if (!name.begins_with("indices") && !name.begins_with(PackedScene::META_POINTER_PROPERTY_BASE + "indices")) {
		return false;
	}
	int index;
	if (name.begins_with("metadata/")) {
		index = name.get_slice("/", 2).to_int();
	} else {
		index = name.get_slice("/", 1).to_int();
	}
	array.set(index, p_value);
	return true;
}
bool EditorPropertyArrayObject::_get(const StringName &p_name, Variant &r_ret) const {