diff --git a/core/dbobject.class.php b/core/dbobject.class.php
index 373635d66..eeee0e3ab 100644
--- a/core/dbobject.class.php
+++ b/core/dbobject.class.php
@@ -2142,28 +2142,23 @@ abstract class DBObject implements iDisplay
 		}
 
 		if ($oAttDef->DuplicatesAllowed()) {
-			return true;
+			return;
 		}
 
+		// To control duplicates go through all the entries and check if the remote has been seen
 		/** @var \ormLinkSet $value */
-		$aModifiedLnk = $value->ListModifiedLinks();
 		$sExtKeyToRemote = $oAttDef->GetExtKeyToRemote();
-		$aExistingRemotesId = $value->GetColumnAsArray($sExtKeyToRemote, true);
-		$aExistingRemotesFriendlyName = $value->GetColumnAsArray($sExtKeyToRemote.'_friendlyname', true);
+		$aCurrentRemoteIds = [];
 		$aDuplicatesFields = [];
-		foreach ($aModifiedLnk as $oModifiedLnk) {
-			$iModifiedLnkId = $oModifiedLnk->GetKey();
-			$iModifiedLnkRemoteId = $oModifiedLnk->Get($sExtKeyToRemote);
-			$aExistingRemotesIdToCheck = array_filter($aExistingRemotesId, function ($iLnkKey) use ($iModifiedLnkId) {
-				return ($iLnkKey != $iModifiedLnkId);
-			}, ARRAY_FILTER_USE_KEY);
-
-			if (!in_array($iModifiedLnkRemoteId, $aExistingRemotesIdToCheck, true)) {
-				continue;
+		$value->rewind();
+		while ($oCurrentLnk = $value->current()) {
+			$iExtKeyToRemote = $oCurrentLnk->Get($sExtKeyToRemote);
+			if (isset($aCurrentRemoteIds[$iExtKeyToRemote])) {
+				$aDuplicatesFields[] = $oCurrentLnk->Get($sExtKeyToRemote.'_friendlyname');
+			} else {
+				$aCurrentRemoteIds[$iExtKeyToRemote] = true;
 			}
-
-			$iLnkId = $oModifiedLnk->GetKey();
-			$aDuplicatesFields[] = $aExistingRemotesFriendlyName[$iLnkId];
+			$value->next();
 		}
 
 		if (!empty($aDuplicatesFields)) {
diff --git a/test/core/ormLinkSetTest.php b/test/core/ormLinkSetTest.php
index cad1c02ea..ff4bf3f29 100644
--- a/test/core/ormLinkSetTest.php
+++ b/test/core/ormLinkSetTest.php
@@ -183,8 +183,6 @@ class ormLinkSetTest extends ItopDataTestCase
      */
     public function testRemoveThenAdd()
     {
-	    self::markTestSkipped('Throws a undefined offset PHP notice in core\dbobject.class.php:2151, to be fixed in N°4047');
-
 	    $oServer = $this->CreateServer(1);
 	    $aPersons = array();
 	    for ($i = 0; $i < 3; $i++) {
diff --git a/test/itop-tickets/itopTicketTest.php b/test/itop-tickets/itopTicketTest.php
index 0bf766764..7990da693 100644
--- a/test/itop-tickets/itopTicketTest.php
+++ b/test/itop-tickets/itopTicketTest.php
@@ -111,8 +111,6 @@ class ItopTicketTest extends ItopDataTestCase
      */
     public function testUpdateImpactedItems_Basic2()
     {
-	    self::markTestSkipped('Throws a undefined offset PHP notice in core\dbobject.class.php:2151, to be fixed in N°4047');
-
 	    $oTicket = $this->CreateTicket(1);
 	    $oServer1 = $this->CreateServer(1);
 	    $oHypervisor1 = $this->CreateHypervisor(1, $oServer1);