According to the manufacturer, this is how it should be. I have one of the old series and have already received a second power supply unit, but without success. Now I have to send the base and the power supply units to France for repair. If it works, it's a great bike.
Yes, I'm talking about the lower series. Apparently, models with a lower number have disconnection problems. The number is indicated on the underside of the device, if I'm not mistaken.