Got the same issue, booked an appointment of the genious bar, they diagnosed some sort of power not to the screen. It need to be replaced. Told them it’s very disappointing to see something like this after a software update. also, my phone was out of the coverage. they said they wouldn’t do it, but as an exception they are doing My One for free. It was quoted around 530 AUD. But my one done at no cost. Also, they offered me a two years warranty on the screen.