If on the first weighing, the scale shows you as one and a half or two kilos heavier and this disappears in subsequent weighings, it is not a device malfunction.
If you turn on the scale while it is in the air (for example, if you are holding it in your hand while putting in the batteries or taking it out from under the cabinet),it will not take its own weight into account. In this way, when you place it on the floor and step on it, the scale will automatically add its own weight to yours.
To avoid this, make sure the scale is started on a flat, hard surface, so that once it is ready to measure, you can step on it without any issues.
Just briefly step on the scale to turn it on, wait for the display to show "0.0" for a few seconds, and then you can step on to measure yourself.