RB63 That's simply WW 'disabling' the charge slot that has just passed, by setting AC start and endtime back to 00:00-00:00.
You can see from the commands sent at 15:59, we disabled Eco mode, Set Discharge power to 2600 and Discharge start and end time 16:00-19:57.
AC charge and end time being set should have no bearing on this.
But what I do notice is that you set Discharge period 2, whereas we set discharge period 1. We exclusively use DIscharge period 1 and the Enable DC Discharge flag.
Is there another setting where you have disabled Discharge period 1 perhaps?