@JustinAtSense and @andy you were right by being septical about my toaster-oven maximum wattage. It is labelled as 1 200 W maximum (giving 10 A).
Strangely enough, Sense is measuring about 2 000 W for this same toaster-oven depending on the displayed tab?!
I turned on successively my baseboard following by my toaster-oven for few second each. Following picture shows Sense’s App Power Meter. We see that the height of the second device (toaster-oven) fits with 1 200 W if the first device (baseboard) is at 2 000 W.
When we look at “Devices” Tab in Sense’s App, we get the following information.
The next picture shows when baseboard is on (nominal 2 000 W).
The next picture shows when toaster-oven is on (nominal 1 200 W).
“Devices” tab always shows my device labelled “Heat 2000W” at 2 161 W, no matter if the baseboard or the toaster-oven is on ! The same happens with Now tab.
The most strange behaviour of Sense’s App is that when my toaster-oven is on, not only Sense shows an impossible and wrong wattage, but it also removed the “Other” device.
@JustinAtSense, you suggested 3 options. #1 can not be used as my Flex Sensors are already dedicated to two other devices. #2 and #3 refer to Support. I guess I should open a ticket for them to review what is happening with “Now” and “Device” tabs in addition to my problem of having two different devices assigned to a single discovered device.