diff --git a/geoportal-service/src/main/java/org/gcube/application/geoportal/service/engine/mongo/ProfiledMongoManager.java b/geoportal-service/src/main/java/org/gcube/application/geoportal/service/engine/mongo/ProfiledMongoManager.java
index a2d9fff..9ed6dd1 100644
--- a/geoportal-service/src/main/java/org/gcube/application/geoportal/service/engine/mongo/ProfiledMongoManager.java
+++ b/geoportal-service/src/main/java/org/gcube/application/geoportal/service/engine/mongo/ProfiledMongoManager.java
@@ -339,13 +339,16 @@ public class ProfiledMongoManager extends MongoManager implements MongoManagerI<
         Project toUpdate=lock(id,"Delete Relation");
 
         try{
+            // SET target UCD to present UCD as default
+            final String toUseTargetUCD = (targetUCD == null || targetUCD.equals(""))? getUseCaseDescriptor().getId():targetUCD;
+
             // check if relation existing
             List<Relationship> relations = toUpdate.getRelationships();
             if(relations!=null && !relations.isEmpty()){
                 int beforeSize = relations.size();
                 toUpdate.getRelationships().removeIf(r ->
                     r.getRelationshipName().equals(relation)&&
-                    r.getTargetUCD().equals(targetUCD)&&
+                    r.getTargetUCD().equals(toUseTargetUCD)&&
                     r.getTargetID().equals(targetId));
                 // update only if something changed
                 if(toUpdate.getRelationships().size()!=beforeSize) {