Filter direction isn't valid for this relationship

I try to create a relationship two views, but Power BI Desktop complains that "The filter direction you selected isn't valid for this relationship". The "many" view has a foreign key int column which references the "one" view's primary key int column. Currently, the "one" view contains three rows (PK 1, 2, 3) and the "many" view contains two rows (FK 2, 3). Any idea why I'm not allowed to create this relationship?