### 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)

picker->set_edit_alpha(p_show_alpha);
}
EditorPropertyColor::EditorPropertyColor() {
	picker = memnew(ColorPickerButton);
	add_child(picker);
	picker->set_flat(true);
	picker->connect("color_changed", callable_mp(this, &EditorPropertyColor::_color_changed));
	picker->connect("popup_closed", callable_mp(this, &EditorPropertyColor::_popup_closed));
	picker->get_popup()->connect("about_to_popup", callable_mp(EditorNode::get_singleton(), &EditorNode::setup_color_picker).bind(picker->get_picker()));
	picker->get_popup()->connect("about_to_popup", callable_mp(this, &EditorPropertyColor::_picker_opening));
}
void EditorPropertyNodePath::_set_read_only(bool p_read_only) {