message: StructureHierarchyManager tweak
diff: @@ -34,6 +34,10 @@ export class StructureHierarchyManager {
  newCurrent.push(ref);
  }
  + if (newCurrent.length === 0 && hierarchy.trajectories[0]?.models) {
  + this.behaviors.currentModels.next(hierarchy.trajectories[0]?.models);
  + }
  +
  this.behaviors.currentModels.next(newCurrent);
  }
  