nut that's the problem - in the pic I posted, the long non-sleep was when car was at home and plugged... nevertheless, will monitor and probably will do as you suggest.Then use one of the two workarounds already mentioned in the thread:
Either:
1) keep the car plugged in if it's at home (this ensures it sleeps)
or
2) Disable IO smart-charging in the app e.g. when you and the car at work. If I'm away with the car, I do this. Then when I park up at home just toggle it back on in the app before plugging in. It's very little faff.