Hi. I have a Cube emtb with the bosch cx2020 engine and purion display. When the display shows 25-26 km/h and cuts the power, My GPS shows 22-23 km/h. Does anyone know how to get the last speed back? The shop where i bought the bike cant help, and everything is mounted correct. Im not looking to tune/derestrict but im missing the last speed when ridning with others.