Reverse does not go in

Hello I’m standing in a parking space and I can’t get out, because the reverse is not going in. I had the problem 3 times before. however, it was always like that until today, that it went off/one again after the engine. however, if I think about it, I had to switch on/off more and more often, until the reverse is wanted again. I was therefore already 3-4x at the workshop. they have then allegedly made a software update and then went again for a while good. the last time not even 3 months ago. now the part is soon 6 years old and I fear that a software update will soon not be enough. has a clue about what this could be about? of course nothing. or what would be worse – they actually don’t know. the car has run 42,000km. Smart Brabus.