Milton's Secret (2016)

11 year-old Milton Adams is growing up in an uncertain world. With his parents constantly stressing about their careers and finances, and the neighborhood bully tormenting him, Milton feels his whole world is in crisis. But when his Grandpa Howard comes to visit, he discovers anxiety about the past and worrying about the future only make things worse and prevent him from finding true happiness moment to moment.

Unfortunately the movie Milton's Secret is not yet available on HBO Max.