My system was updated to 309 on 25th June, and I've just noticed that, since then, discharge limit has been behaving oddly.
I (ab)use discharge timers to implement a pause-discharge before charging. (Yes, I know there's a proper pause timer, but I use that for something else.) So I have discharge timer #3 set to run from 23:30 to 23:59, with a discharge limit of 100%, the idea being that it will pause discharge because it is always below that limit.
On 305 and 307, this worked fine. But on 309, it seems to charge the battery from grid at low power. As an experiment yesterday, I moved the timer to start at 2345, and sure enough, the low-power charge was deferred until 2345, which hopefully rules out some other factor. Charging is at about 300W, even though the charging limit was configured to be around 1kW (in preparation for slow overnight charge). So not sure where 300W comes from, other than that's about the power it uses even when max charging power is set to 0W.
307 with timer at 2330: 
309 with timer at 2330: 
309 with timer at 2345: 
(My cheap rate starts at 23:30 so it makes sense to run from grid rather than battery. But I want to defer active charging until after midnight for 2 reasons: idling the battery may allow it to rebalance; and for accounting purposes I'd prefer the grid-charging to happen within one calendar day.)