IoTaWatt - total_power.wh defined

So confused - I’m setting up a wallpanel on a Fire tablet. I added a nice SAF view of current power W and power total Wh.

But I get different numbers for total_power.wh on the Energy dash

and the total_power.wh entity

Why would total_power.wh differ between the Energy dashboard and the entity?
Also I can’t find a verified definition of total_power.wh - is it the power consumed since midnight in my local time, the last 24 hours, or something else?
Thanks for leading the blind through the power grid!