PV output and grid pull has just gone very variable

See chart below for today. Was working fine this morning and now is generating 4w and 4kW alternately, then pulling from the grid when battery is fully charged. Not sure what is going on here. Weather is still clear blue sky.

Any ideas:

SimonByrne if you have a Gen 2 inverter and all panels on one string I think you need the firmware update, contact GE support and request it, v909 I think it is

ok thanks. will drop them a mail