Three tracks from the EP, You Shouldn't Be Here, E.L.F, and One Night, were self-released by SOULJI on October 26, 2017 as "Black Mask EP Pt. 1." At some point between then and the release of the complete EP on May 3, 2018, those tracks were removed from Spotify so that they could be released again by Monstercat.
To find an EP, navigate to the tab that the artist's name begins with. For example, Laszlo's Closer EP would be located under the L tab and then listed beside "Laszlo".