On my 2014 Pilot, the hatch assist mechanism has stopped working, and I am receiving a "Hatch Open" warning on the instrument panel.
What has happened? There is no damage that is obvious, it just quit working today.
This can also happen if the rear windows isn't detected as full-closed. The same switch activates the interior light, so that might be a telltale that the window isn't closed or the switch isn't working.