Sometimes the Good Kill (2017) on Netflix

Plot summary

At the Abbey, a death is treated as an internal matter. Sister Talia is put at the center of the inquiry, and the newly elected Mother Superior gives her strict orders: establish the truth about the death and keep the community undisturbed. When a second sister is found dead, Talia is pressed to identify the killer. The search carries her further into the Abbey's affairs and what the sisters there have kept among themselves. It also forces her to reckon with the life she led before she took her vows, since she cannot finish the task she has been given without doing so.