When a DCI that has the option Show last value in object overview ticked is disabled, the last value collected remains visible in the object overview.
Not sure if that is on purpose, but it seems a bit counter intuitive to show something that's been disabled in the overview, especially as it's not indicated in that overview that this DCI has been disabled. I did not double-check the Show last value in object tooltips, but I would guess it will have the same behaviour.