Wrong Move (1975)

Six days in the life of Wilhelm: a detached man without qualities. He wants to write, so his mother gives him a ticket to Bonn, telling him to live. On the train he meets an older man, an athlete in the 1936 Olympics, and his mute teen companion, Mignon. She's an acrobat in market squares for spare change.

Unfortunately the movie Wrong Move is not yet available on HBO Max.