Metabo lawn-mower RM 36-18 LTX BL 36 review - problems after one month of use

This lawn-mower always throw some grass away. It is a little depends of cutting height (in higher position it works better, in lower - worse). This problem not depends of weather, speed, grass dry, etc. Also sometime it can accidentally switch itself to lower position. This is new device, and all this happens from beginning of use.