### 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)

String type = base_type;
	Callable callable = get_edited_property_value();
	edit->set_text("Callable");
	edit->set_disabled(true);
	edit->set_icon(get_theme_icon(SNAME("Callable"), SNAME("EditorIcons")));
}
void EditorPropertyCallable::_bind_methods() {
}
EditorPropertyCallable::EditorPropertyCallable() {
	edit = memnew(Button);
	add_child(edit);
	add_focusable(edit);
}
void EditorPropertyFloat::_set_read_only(bool p_read_only) {
	spin->set_read_only(p_read_only);
}
void EditorPropertyFloat::_value_changed(double val) {
	if (setting) {
		return;
	}
	if (angle_in_radians) {
		val = Math::deg_to_rad(val);
	}
	emit_changed(get_edited_property(), val);
}
void EditorPropertyFloat::update_property() {