EQB350 4matic – Problems with the locking system

Hello together, with our EQB (EZ 6/24) we have had the following problem for a few days: If we open the car, be it with the finger on the handle (Keyless Go), be it with the key switch, always only opens the driver’s door. In order to open the other doors, you always have to press a second time. Can it be that I accidentally have changed something? I find unfortunately nothing on this topic. Thanks for tips! D.