Issue 8392 fix improved

Author: kirashet666

app/code/Magento/Catalog/Model/ProductLink/CollectionProvider.php

@@ -53,7 +53,14 @@ public function getCollection(\Magento\Catalog\Model\Product $product, $type)
             $output[$item->getId()] = $converter->convert($item);
         }
         foreach ($output as $item) {
-            $realoutput[$item["position"]] = $item;
+            $itemPosition = $item["position"];
+            if (!isset($realoutput[$itemposition])) {
+                $realoutput[$itemPosition] = $item;
+            }
+            else {
+                $newPosition = $itemPosition+1;
+                $realoutput[$newPosition] = $item;
+            }
         }
         ksort($realoutput);
         return $realoutput;