diff --git a/public/main/inc/lib/groupmanager.lib.php b/public/main/inc/lib/groupmanager.lib.php
index 1fbb9115c4..38e56cb78c 100644
--- a/public/main/inc/lib/groupmanager.lib.php
+++ b/public/main/inc/lib/groupmanager.lib.php
@@ -226,13 +226,13 @@ class GroupManager
         $places = (int) $places;
 
         // Default values
-        $docState = self::TOOL_PRIVATE;
-        $calendarState = self::TOOL_PRIVATE;
-        $workState = self::TOOL_PRIVATE;
-        $anonuncementState = self::TOOL_PRIVATE;
-        $forumState = self::TOOL_PRIVATE;
-        $wikiState = self::TOOL_PRIVATE;
-        $chatState = self::TOOL_PRIVATE;
+        $docState = CGroup::TOOL_PRIVATE;
+        $calendarState = CGroup::TOOL_PRIVATE;
+        $workState = CGroup::TOOL_PRIVATE;
+        $anonuncementState = CGroup::TOOL_PRIVATE;
+        $forumState = CGroup::TOOL_PRIVATE;
+        $wikiState = CGroup::TOOL_PRIVATE;
+        $chatState = CGroup::TOOL_PRIVATE;
         $selfRegAllowed = 0;
         $selfUnregAllwoed = 0;
         $documentAccess = 0;
@@ -266,8 +266,7 @@ class GroupManager
             $category = Container::getGroupCategoryRepository()->find($category_id);
         }
 
-        $group = new CGroup();
-        $group
+        $group = (new CGroup())
             ->setName($name)
             ->setCategory($category)
             ->setMaxStudent($places)
diff --git a/src/CourseBundle/Entity/CGroup.php b/src/CourseBundle/Entity/CGroup.php
index 579ff28069..f5251071b2 100644
--- a/src/CourseBundle/Entity/CGroup.php
+++ b/src/CourseBundle/Entity/CGroup.php
@@ -31,10 +31,15 @@ use Symfony\Component\Validator\Constraints as Assert;
  *     }
  * )
  *
- * @ORM\Entity
+ * @ORM\Entity(repositoryClass="Chamilo\CourseBundle\Repository\CGroupRepository")
  */
 class CGroup extends AbstractResource implements ResourceInterface
 {
+    public const TOOL_NOT_AVAILABLE = 0;
+    public const TOOL_PUBLIC = 1;
+    public const TOOL_PRIVATE = 2;
+    public const TOOL_PRIVATE_BETWEEN_USERS = 3;
+
     /**
      * @ORM\Column(name="iid", type="integer")
      * @ORM\Id
@@ -70,6 +75,7 @@ class CGroup extends AbstractResource implements ResourceInterface
     /**
      * @ORM\Column(name="max_student", type="integer")
      */
+    #[Assert\NotBlank]
     protected int $maxStudent;
 
     /**
@@ -141,6 +147,21 @@ class CGroup extends AbstractResource implements ResourceInterface
         $this->status = true;
         $this->members = new ArrayCollection();
         $this->tutors = new ArrayCollection();
+
+        // Default values
+        $defaultVisibility = self::TOOL_PRIVATE;
+
+        $this->docState = $defaultVisibility;
+        $this->calendarState = $defaultVisibility;
+        $this->workState = $defaultVisibility;
+        $this->announcementsState = $defaultVisibility;
+        $this->forumState = $defaultVisibility;
+        $this->wikiState = $defaultVisibility;
+        $this->chatState = $defaultVisibility;
+        $this->documentAccess = $defaultVisibility;
+
+        $this->selfRegistrationAllowed = false;
+        $this->selfUnregistrationAllowed = false;
     }
 
     public function __toString(): string
diff --git a/tests/CourseBundle/Repository/CGroupRepositoryTest.php b/tests/CourseBundle/Repository/CGroupRepositoryTest.php
new file mode 100644
index 0000000000..364d026e1b
--- /dev/null
+++ b/tests/CourseBundle/Repository/CGroupRepositoryTest.php
@@ -0,0 +1,40 @@
+<?php
+
+declare(strict_types=1);
+
+/* For licensing terms, see /license.txt */
+
+namespace Chamilo\Tests\CourseBundle\Repository;
+
+use Chamilo\CourseBundle\Entity\CGroup;
+use Chamilo\CourseBundle\Repository\CGroupRepository;
+use Chamilo\Tests\AbstractApiTest;
+use Chamilo\Tests\ChamiloTestTrait;
+
+class CGroupRepositoryTest extends AbstractApiTest
+{
+    use ChamiloTestTrait;
+
+    public function testCreate(): void
+    {
+        self::bootKernel();
+
+        $em = self::getContainer()->get('doctrine')->getManager();
+        $repo = self::getContainer()->get(CGroupRepository::class);
+
+        $course = $this->createCourse('new');
+        $teacher = $this->createUser('teacher');
+
+        $item = (new CGroup())
+            ->setName('Group')
+            ->setParent($course)
+            ->setCreator($teacher)
+            ->setMaxStudent(100)
+        ;
+        $this->assertHasNoEntityViolations($item);
+        $em->persist($item);
+        $em->flush();
+
+        $this->assertSame(1, $repo->count([]));
+    }
+}