diff --git a/api/src/chat/repositories/block.repository.ts b/api/src/chat/repositories/block.repository.ts
index 78903a3c..ec2a3f64 100644
--- a/api/src/chat/repositories/block.repository.ts
+++ b/api/src/chat/repositories/block.repository.ts
@@ -140,12 +140,12 @@ export class BlockRepository extends BaseRepository<
 
         // Step 1: Map IDs and Category
         const objIds = ids.map((id) => new Types.ObjectId(id));
-        const objCategoryId = new Types.ObjectId(categoryId);
+        const sourceCategoryId = movedBlocks[0].category;
 
-        // Step 2: Find other blocks
+        // Step 2: Find blocks in source category that reference the moved blocks
         const otherBlocks = await this.find({
           _id: { $nin: objIds },
-          category: { $ne: objCategoryId },
+          category: sourceCategoryId,
           $or: [
             { attachedBlock: { $in: objIds } },
             { nextBlocks: { $in: objIds } },
@@ -154,7 +154,7 @@ export class BlockRepository extends BaseRepository<
         // Step 3: Update blocks in the provided scope
         await this.prepareBlocksInCategoryUpdateScope(categoryId, ids);
 
-        // Step 4: Update external blocks
+        // Step 4: Update blocks in source category
         await this.prepareBlocksOutOfCategoryUpdateScope(otherBlocks, ids);
       }
     }
@@ -178,18 +178,27 @@ export class BlockRepository extends BaseRepository<
     });
 
     for (const { id, nextBlocks, attachedBlock } of blocks) {
-      const updatedNextBlocks = nextBlocks.filter((nextBlock) =>
-        ids.includes(nextBlock),
-      );
+      try {
+        const updatedNextBlocks = nextBlocks.filter((nextBlock) =>
+          ids.includes(nextBlock),
+        );
 
-      const updatedAttachedBlock = ids.includes(attachedBlock || '')
-        ? attachedBlock
-        : null;
+        const updatedAttachedBlock = ids.includes(attachedBlock || '')
+          ? attachedBlock
+          : null;
 
-      await this.updateOne(id, {
-        nextBlocks: updatedNextBlocks,
-        attachedBlock: updatedAttachedBlock,
-      });
+        const updates: Partial<Block> = {
+          nextBlocks: updatedNextBlocks,
+          attachedBlock: updatedAttachedBlock,
+        };
+
+        await this.updateOne(id, updates);
+      } catch (error) {
+        this.logger?.error(
+          `Failed to update block ${id} during in-category scope update.`,
+          error,
+        );
+      }
     }
   }
 
@@ -206,16 +215,33 @@ export class BlockRepository extends BaseRepository<
     ids: string[],
   ): Promise<void> {
     for (const block of otherBlocks) {
-      if (block.attachedBlock && ids.includes(block.attachedBlock)) {
-        await this.updateOne(block.id, { attachedBlock: null });
-      }
+      try {
+        const updates: Partial<Block> = {};
 
-      const nextBlocks = block.nextBlocks?.filter(
-        (nextBlock) => !ids.includes(nextBlock),
-      );
+        // Check if the block has an attachedBlock
+        if (block.attachedBlock) {
+          if (ids.includes(block.attachedBlock)) {
+            updates.attachedBlock = null;
+          }
+        } else {
+          // Only check nextBlocks if there is no attachedBlock
+          const filteredNextBlocks = block.nextBlocks?.filter(
+            (nextBlock) => !ids.includes(nextBlock),
+          );
 
-      if (nextBlocks?.length) {
-        await this.updateOne(block.id, { nextBlocks });
+          if (filteredNextBlocks?.length !== block.nextBlocks?.length) {
+            updates.nextBlocks = filteredNextBlocks || [];
+          }
+        }
+
+        if (Object.keys(updates).length > 0) {
+          await this.updateOne(block.id, updates);
+        }
+      } catch (error) {
+        this.logger?.error(
+          `Failed to update block ${block.id} during out-of-category scope update.`,
+          error,
+        );
       }
     }
   }
diff --git a/frontend/public/locales/en/translation.json b/frontend/public/locales/en/translation.json
index 5173d80f..50dbac01 100644
--- a/frontend/public/locales/en/translation.json
+++ b/frontend/public/locales/en/translation.json
@@ -118,6 +118,7 @@
     "logout_failed": "Something went wrong during logout",
     "duplicate_labels_not_allowed": "Duplicate labels are not allowed",
     "duplicate_block_error": "Something went wrong while duplicating block",
+    "move_block_error": "Something went wrong. Unable to move block",
     "image_error": "Image not found",
     "file_error": "File not found",
     "audio_error": "Audio not found",
diff --git a/frontend/public/locales/fr/translation.json b/frontend/public/locales/fr/translation.json
index 8bc2f29f..a50eac87 100644
--- a/frontend/public/locales/fr/translation.json
+++ b/frontend/public/locales/fr/translation.json
@@ -118,6 +118,7 @@
     "logout_failed": "Une erreur s'est produite lors de la déconnexion",
     "duplicate_labels_not_allowed": "Les étiquettes en double ne sont pas autorisées",
     "duplicate_block_error": "Une erreur est survenue lors de la duplication du bloc",
+    "move_block_error": "Une erreur est survenue. Impossible de déplacer le bloc",
     "image_error": "Image introuvable",
     "file_error": "Fichier introuvable",
     "audio_error": "Audio introuvable",
diff --git a/frontend/src/components/visual-editor/v2/Diagrams.tsx b/frontend/src/components/visual-editor/v2/Diagrams.tsx
index f6708e09..5f03b6b7 100644
--- a/frontend/src/components/visual-editor/v2/Diagrams.tsx
+++ b/frontend/src/components/visual-editor/v2/Diagrams.tsx
@@ -559,9 +559,14 @@ const Diagrams = () => {
               },
             });
 
-            onCategoryChange(
-              categories.findIndex(({ id }) => id === targetCategoryId),
+            const targetCategoryIndex = categories.findIndex(
+              ({ id }) => id === targetCategoryId,
             );
+
+            onCategoryChange(targetCategoryIndex);
+          },
+          onError: () => {
+            toast.error(t("message.move_block_error"));
           },
         },
       );