### 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)

for (int i = 0; i < 6; i++) {
		spin[i]->set_read_only(p_read_only);
	}
}
void EditorPropertyTransform2D::_value_changed(double val, const String &p_name) {
	if (setting) {
		return;
	}
	Transform2D p;
	p[0][0] = spin[0]->get_value();
	p[1][0] = spin[1]->get_value();
	p[2][0] = spin[2]->get_value();
	p[0][1] = spin[3]->get_value();
	p[1][1] = spin[4]->get_value();
	p[2][1] = spin[5]->get_value();
	emit_changed(get_edited_property(), p, p_name);
}
void EditorPropertyTransform2D::update_property() {