### 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)

node = parent->_get_child_by_name(snames[n.name]);
#ifdef DEBUG_ENABLED
				if (!node) {
					WARN_PRINT(String("Node '" + String(ret_nodes[0]->get_path_to(parent)) + "/" + String(snames[n.name]) + "' was modified from inside an instance, but it has vanished.").ascii().get_data());
				}
#endif
			}
		} else {
			
			Object *obj = ClassDB::instantiate(snames[n.type]);
			node = Object::cast_to<Node>(obj);
			if (!node) {
				if (obj) {
					memdelete(obj);
					obj = nullptr;
				}
				if (ResourceLoader::is_creating_missing_resources_if_class_unavailable_enabled()) {
					missing_node = memnew(MissingNode);
					missing_node->set_original_class(snames[n.type]);
					missing_node->set_recording_properties(true);
					node = missing_node;
					obj = missing_node;
				} else {
					WARN_PRINT(vformat("Node %s of type %s cannot be created. A placeholder will be created instead.", snames[n.name], snames[n.type]).ascii().get_data());
					if (n.parent >= 0 && n.parent < nc && ret_nodes[n.parent]) {
						if (Object::cast_to<Control>(ret_nodes[n.parent])) {
							obj = memnew(Control);
						} else if (Object::cast_to<Node2D>(ret_nodes[n.parent])) {
							obj = memnew(Node2D);
#ifndef _3D_DISABLED