Simon_C, note to self and for info.
After around 12 hours of battery and BMS over voltage, the battery self recovered. The temperature dropped overnight and the mostly 31 W discharge reduced the voltage sufficiently.
The battery capacity on the portal returned to 9.5 kWh from 6.4 around the same time as the recovery to 100% SoC.
Manually discharged to grid for a few hours to reduce the battery %SoC and reduced the charge power so it will be a lot later in the day when %SoC reaches 100%.
Is it something to do with v3013 combined with increasing temperature with the battery at 100% for a long period?