can't rotate, scale, grab only cube in object mode

Question

as I write in the title, I can't rotate, grabe and scale the cube in object mode in blender 2.9. When I try to grab the cube, the origin (the little sphere) moves but not the cube; I try to unselect "only locations" in trasform pivot point menù, but it's not select and it doesn't work. when I try to grab, rotate and scale camera or lamp it works.