After 2-3 days, I noticed that the kettle constantly (as soon as it is plugged in, even without running) "whistles" at a high frequency, like a cheap "Made-in-China" charger.... It gets even louder during operation... Since I have sensitive hearing, this is unbearable for me... Do you also have this "whistling" or is this a defect (also complained about in r.bonvin's review, also defective?)?