7Foretown I can't remember if you ever said which tariff you are on. Is it Flux ?
Unfortunately, it turns out that timed-discharge behaves very differently on gen-1 systems and newer systems. Did you follow the discussion on
https://community.givenergy.cloud/d/4284-confused-about-export
Your system clearly behaves like mine, and 'timed discharge' is just a better 'timed export'. But on older systems, configuring a timed discharge like this actually serves to inhibit solar charging during the time window. (ie from 16:00). [If I correctly remember the takeaway - I'll need to check.] This would make sense if you are on flux, since exporting is preferable to charging the battery.
Unfortunately, on your system, this has the effect of exporting to grid if an opportunity presents itself before 7am. Which is exactly what happened - your AC charging (which takes precendence) finished around 3am or something, and that immediately allowed the timed discharge to happen.
If it was me, I'd turn off that smart tariff stuff immediately... But then I'm much happier controlling my system myself, using API calls (and I'm currently working on some modbus-based monitoring...). And solar forecasting (the tricky part) is not currently something I need to worry about.