App graph not showing negative usage

It seems that the app is not showing any negative power usage in the history graph.

I have a Plus 2PM near a place where a small solar panel is installed. If there's no sun, it measures the usage and shows the historical data correctly in the app.

If the sun is shining and usage is less than what is produced, it shows indeed negative power, which is correct. However, the usage graph shows positive values instead of negative ones.

I guess this is a bug?

Support wrote:

Yes, at the moment only EM devices can record negative consumption, but we are working on this for every Gen2 device that has power metering. We can't advise on ETA when this will be ready or publicly available.