2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/161373We classify isometric actions of compact Lie groups on quaternionic-Kähler projective spaces with vanishing homogeneity rank. We also show that they are not in general quaternion-coisotropic.18 pages. The present version corrects and improves the previous version of the paper entitled "3-coisotropic actions on positive quaternionic-Kaehler manifolds". A key example has been addedDifferential Geometry53C26; 57S15text