### 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)

cb->connect("pressed", callable_mp(this, &EditorPropertyFlags::_flag_toggled).bind(flag_index));
		add_focusable(cb);
		vbox->add_child(cb);
		flags.push_back(cb);
		
		if (first) {
			set_label_reference(cb);
			first = false;
		}
	}
}
void EditorPropertyFlags::_bind_methods() {
}
EditorPropertyFlags::EditorPropertyFlags() {
	vbox = memnew(VBoxContainer);
	add_child(vbox);
}
void EditorPropertyLayersGrid::_rename_pressed(int p_menu) {
	
	if (renamed_layer_index == -1) {
		return;
	}
	String name = names[renamed_layer_index];
	rename_dialog->set_title(vformat(TTR("Renaming layer %d:"), renamed_layer_index + 1));
	rename_dialog_text->set_text(name);
	rename_dialog_text->select(0, name.length());
	rename_dialog->popup_centered(Size2(300, 80) * EDSCALE);
	rename_dialog_text->grab_focus();
}
void EditorPropertyLayersGrid::_rename_operation_confirm() {