### 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)

Variant current = get_edited_property_value();
	if (current.get_type() == Variant::NIL) {
		options->select(-1);
		return;
	}
	int64_t which = current;
	for (int i = 0; i < options->get_item_count(); i++) {
		if (which == (int64_t)options->get_item_metadata(i)) {
			options->select(i);
			return;
		}
	}
}
void EditorPropertyEnum::setup(const Vector<String> &p_options) {
	options->clear();
	int64_t current_val = 0;
	for (int i = 0; i < p_options.size(); i++) {
		Vector<String> text_split = p_options[i].split(":");
		if (text_split.size() != 1) {
			current_val = text_split[1].to_int();
		}
		options->add_item(text_split[0]);
		options->set_item_metadata(i, current_val);
		current_val += 1;
	}
}
void EditorPropertyEnum::set_option_button_clip(bool p_enable) {