Logbook Empty

Hey guys - since some version of 0.4x I’ve noticed that my logbook is always empty OR will randomly log events at the incorrect times. I have validated that my Rpi has the correct time. Anyone have any ideas where I should start looking?

only potentially relevant log I see is
2017-08-16 01:25:35 WARNING (Recorder) [homeassistant.components.recorder] Ended unfinished session (id=73 from 2017-08-16 05:15:05.073579)
2017-08-16 01:25:36 ERROR (MainThread) [homeassistant.core] Error doing job: Task exception was never retrieved

and

2017-08-18 22:15:15 ERROR (Recorder) [homeassistant.components.recorder.util] Error executing query: Object of type ‘HomeAssistant’ is not JSON serializable

In case anyone is interested… https://github.com/home-assistant/home-assistant/issues/8297