### 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)

if (setting) {
		return;
	}
	edit_euler.x = euler[0]->get_value();
	edit_euler.y = euler[1]->get_value();
	edit_euler.z = euler[2]->get_value();
	Vector3 v;
	v.x = Math::deg_to_rad(edit_euler.x);
	v.y = Math::deg_to_rad(edit_euler.y);
	v.z = Math::deg_to_rad(edit_euler.z);
	Quaternion temp_q = Quaternion::from_euler(v);
	spin[0]->set_value(temp_q.x);
	spin[1]->set_value(temp_q.y);
	spin[2]->set_value(temp_q.z);
	spin[3]->set_value(temp_q.w);
}
void EditorPropertyQuaternion::_value_changed(double val, const String &p_name) {
	if (setting) {
		return;
	}
	Quaternion p;
	p.x = spin[0]->get_value();
	p.y = spin[1]->get_value();
	p.z = spin[2]->get_value();
	p.w = spin[3]->get_value();
	emit_changed(get_edited_property(), p, p_name);
}
bool EditorPropertyQuaternion::is_grabbing_euler() {