### 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)

case LAYER_NAVIGATION_3D: {
			basename = "layer_names/3d_navigation";
			layer_group_size = 4;
			layer_count = 32;
		} break;
		case LAYER_AVOIDANCE: {
			basename = "layer_names/avoidance";
			layer_group_size = 4;
			layer_count = 32;
		} break;
	}
	Vector<String> names;
	Vector<String> tooltips;
	for (int i = 0; i < layer_count; i++) {
		String name;
		if (ProjectSettings::get_singleton()->has_setting(basename + vformat("/layer_%d", i + 1))) {
			name = GLOBAL_GET(basename + vformat("/layer_%d", i + 1));
		}
		if (name.is_empty()) {
			name = vformat(TTR("Layer %d"), i + 1);
		}
		names.push_back(name);
		tooltips.push_back(name + "\n" + vformat(TTR("Bit %d, value %d"), i, 1 << i));
	}
	grid->names = names;
	grid->tooltips = tooltips;
	grid->layer_group_size = layer_group_size;
	grid->layer_count = layer_count;
}
void EditorPropertyLayers::set_layer_name(int p_index, const String &p_name) {