### 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)

warning_dialog->popup_centered();
}
void EditorPropertyQuaternion::_notification(int p_what) {
	switch (p_what) {
		case NOTIFICATION_ENTER_TREE:
		case NOTIFICATION_THEME_CHANGED: {
			const Color *colors = _get_property_colors();
			for (int i = 0; i < 4; i++) {
				spin[i]->add_theme_color_override("label_color", colors[i]);
			}
			for (int i = 0; i < 3; i++) {
				euler[i]->add_theme_color_override("label_color", colors[i]);
			}
			edit_button->set_icon(get_theme_icon(SNAME("Edit"), SNAME("EditorIcons")));
			euler_label->add_theme_color_override(SNAME("font_color"), get_theme_color(SNAME("property_color"), SNAME("Editor")));
			warning->set_icon(get_theme_icon(SNAME("NodeWarning"), SNAME("EditorIcons")));
			warning->add_theme_color_override(SNAME("font_color"), get_theme_color(SNAME("warning_color"), SNAME("Editor")));
		} break;
	}
}
void EditorPropertyQuaternion::_bind_methods() {