diff --git a/packages/core/src/plugins/keymap.ts b/packages/core/src/plugins/keymap.ts
index 019655fa..6a196034 100644
--- a/packages/core/src/plugins/keymap.ts
+++ b/packages/core/src/plugins/keymap.ts
@@ -6,6 +6,12 @@ import { clearMarks } from '../commands';
 export const edimBasicKeymapPlugins = (): Plugin[] => {
   return [
     keymap({
+      /**
+       * Prevents focus from leaving when the Tab key is pressed.
+       */
+      'Shift-Tab': () => true,
+      Tab: () => true,
+
       /**
        * Switch to the default node of the Schema when the first node is empty.
        */
diff --git a/packages/core/src/plugins/virtual-cursor.ts b/packages/core/src/plugins/virtual-cursor.ts
index d5f2f0fa..9306f370 100644
--- a/packages/core/src/plugins/virtual-cursor.ts
+++ b/packages/core/src/plugins/virtual-cursor.ts
@@ -65,8 +65,16 @@ export function edimVirtualCursorPlugins(): PMPlugin[] {
             }
           }
 
+          const hasInexclusiveMark = marks.find(
+            (m) => m?.type.spec.inclusive === false,
+          );
+
           // Move the cursor and also change the stored marks
-          if (event.key === 'ArrowLeft' && $pos.textOffset === 1) {
+          if (
+            event.key === 'ArrowLeft' &&
+            $pos.textOffset === 1 &&
+            !hasInexclusiveMark
+          ) {
             view.dispatch(
               view.state.tr
                 .setSelection(
@@ -80,7 +88,8 @@ export function edimVirtualCursorPlugins(): PMPlugin[] {
           if (
             event.key === 'ArrowRight' &&
             $pos.textOffset + 1 ===
-            $pos.parent.maybeChild($pos.index())?.nodeSize
+              $pos.parent.maybeChild($pos.index())?.nodeSize &&
+            !hasInexclusiveMark
           ) {
             view.dispatch(
               view.state.tr
diff --git a/packages/mention/src/schemas/mention.ts b/packages/mention/src/schemas/mention.ts
index c7048d89..753e99c7 100644
--- a/packages/mention/src/schemas/mention.ts
+++ b/packages/mention/src/schemas/mention.ts
@@ -24,6 +24,7 @@ export const edimMentionMarks = (
 
   const markSpec: MarkSpec = {
     inclusive: false,
+    excludes: '_',
     attrs: {
       data_id: {
         default: '',