W to kWh not working for Microwave


I have a couple of Watt measuring devices, Dishwasher, Heatpump etc. And I have done the usual way to get kWh data i.e: Create one “Integration - Riemann sum integral sensor” to get Watt converted to kWh, then I create a Utility Meter to be able to get that in daily/weekly etc values.

But, I see a strange behivor for the Microwave, I do not understand why that would behave differently then the other things a have done this for, the only thing I can think of is that the Microwave is producing a very high Watt measurement under a short amount of time.

Anyone else encountered this problem?
As I said, measurements are fine for the other appliances I have watt meters on (compared to the actual data from Tuya app)

I add some screenshots:

This is the Power meter coming from Tuya:

Here is my "Integration - Riemann sum integral sensor

You should use the method “left” in the Riemann sensor for these kind of devices.

Thanks a lot for that answer, when you say devices like this, you mean Microwaves? Or all kind of devices? Since most other devices seemed to work well