I had this rice cooker before.:
https://safran-eu.de/sonstiges/haushaltsgeraete/1095/reiskocher-2-personen-pars-khazar
Although it looks almost the same, it worked as described above.
The new one is much better it seems to have a temperature sensor. Only when the water has evaporated does the timer start running.
And it is permanently on boil. Unfortunately, I can therefore not write down the time interval.
However, my problem has been solved, I was only interested in not having two devices for almost the same purpose lying around in my kitchen. The only pity is that there are no Persian rice cookers that are reasonably manufactured, it all looks very cheap.
I'm not sure anymore how this thing works.