Check in the App under "Imprints on e-mark" if you have really saved imprints on your device. Try to replace one of the imprints or save a new one and try again to switch. Maybe the imprints were accidentially deleted from your device. For changing the position, you need to tap four times on the e-mark with a small break between the first double click. Watch our video 'How to change the imprints stored on the e-mark' for exact sequence of steps.