Update: Mine was in the garage yesterday and is not a hardware problem which I was convinced it was. Like you said, it's been reported so I'm waiting to hear back from them.Mine screen started to work again after a couple of days, but my dealer still wanted to investigate it (and some other issues I have with the car).
They did not find anything for reverse screen problem in my car, but they said that others also have reported this and that Seat is working on a solution.
They fitted a new rear interior light also as I had some issues with it.
They did some sort of a reset too for the reoccurring front assist etc going off every so often. We'll see what happens!!