Sprintshift gives alarm when gear is inserted.

Hi Sprinterfreunde, I have recently had the problem that my big driver (a Sprinter-based mobile home) emits a beep tone/alarm signal from the cockpit as soon as I have put the gear in (on A) and then get off the brake. As soon as I step on the gas, it stops again. In the meantime, in which no pedal is actuated, he screams quasi. If I ignore it and do not press a pedal, the gearbox switches again to “N”. Otherwise I have no impairment and it switches What the hell is that?!? No one has ever posted such a problem anywhere and I am in despair! Do I really have to use it for nothing at MB?? It is a pre-programmed warning signal – that must be clearly identifiable! Thank you for your advice!