Negative values in kWh histogram

Hi all,

We recently experienced a couple of power cuts.

I only noticed later on that this seems to have resulted in a couple of negative values in the Histogram. Specifically at 1,200, 1,300 and 1,400 watts.

This also results in the report module upper threshold drawing an upside down bar that goes back down into the yellow.

Is this expected behaviour and if not is there any way we can remove those specific histogram values?

Cheers, Iain