Inverter incorrectly showing very low usage

We just had a Hypervolt car charger fitted today, and now the inverter thinks we are only using 151W in our house, which is rather unlikely, especially since the car is plugged in. We also have a Haarvi sensor which is correctly showing about 7KW usage.

The charger installer had no idea why, we can't figure it out either. We've tried forcing the CT clamps as far apart as we can in case it was interference, but don't seem to get any improvment.

Does anyone have any idea what is going on and how we can fix it? At this rate its going to fill the battery and start exporting as it thinks we aren't using anything!

Update - found the problem - it had all been switched off when he cut the power to do the install. All working as it should be now!
Moral of the story - lift all the flaps before thinking you can't see any problem!