The Deserted Piazza (1971)

A sculptor, in the company of a disciple, isolates himself in an underground room, no longer able to identify with a society without any value. His personal revolution is no longer to create anything, but simply to wait. However, he is forced to receive unwelcome visits that keep him in touch with the absurdities of the outside world. When he finally decides to go out to the surface, he will find a world worse than when he left it.

Unfortunately the movie The Deserted Piazza is not yet available on HBO Max.