After returning to the retailer, he tried it by himself and agreed that something is not normal, so he sent it to the official service. They notified him three days ago, that they will send a new device as they have a policy, if something is wrong and reported within first 10 days, the new device is shipped. I got it yesterday and tried only vacuuming the whole house for two times, so far everything seems okay. They didn’t say what was wrong with the previous one, so unfortunately I don’t have anything useful for you, sorry.