Quiet Comes the Dawn (2019)

Since her brother died, Svetlana has been suffering from terrifying nightmares. Desperate, she goes to an academic institution for help, where she is proposed that she participate in an experimental therapy. Svetlana accepts and, together with other patients, she is placed into a collective lucid dream. At dawn, when they wake up, the group discovers that they have entered an alternate reality more terrifying than their worst nightmares.