Lost (2021)

The film tells the story of siblings Nina and Ben, who live together in an apartment on the 21st floor of the Maria Theresa high-rise in Wels. Their parents aren't with them. The situation seems problematic. Although Ben is already an adult, he's currently jobless and, after his girlfriend Tamara left him, spends his days in his room, refusing to let even his sister get close to him. When Nina returns from shopping one day, Ben has disappeared. She goes looking for him.