Hello,
When an ObjectBillboards 's billboards are not at the local origin, and the ObjectBillboards itself is a child of a transformed node, then the gizmo of the billboards is not displayed in the correct location.
Above, you can see the billboard_3 gizmo is not in the correct place, because the parent WorldExpression has been rotated. The billboard_3 image is in the correct place, though.
Thanks