diff --git a/administrator/components/com_content/src/Model/ArticleModel.php b/administrator/components/com_content/src/Model/ArticleModel.php
index 7903582d1f989..d613d2e592884 100644
--- a/administrator/components/com_content/src/Model/ArticleModel.php
+++ b/administrator/components/com_content/src/Model/ArticleModel.php
@@ -163,9 +163,6 @@ protected function cleanupPostBatchCopy(TableInterface $table, $newId, $oldId)
 
 		$this->workflowCleanupBatchMove($oldId, $newId);
 
-		// Register FieldsHelper
-		\JLoader::register('FieldsHelper', JPATH_ADMINISTRATOR . '/components/com_fields/helpers/fields.php');
-
 		$oldItem = $this->getTable();
 		$oldItem->load($oldId);
 		$fields = FieldsHelper::getFields('com_content.article', $oldItem, true);
@@ -487,8 +484,7 @@ public function getItem($pk = null)
 	 */
 	public function getForm($data = array(), $loadData = true)
 	{
-		$app  = Factory::getApplication();
-		$user = $app->getIdentity();
+		$user = Factory::getApplication()->getIdentity();
 
 		// Get the form.
 		$form = $this->loadForm('com_content.article', 'article', array('control' => 'jform', 'load_data' => $loadData));
@@ -498,62 +494,38 @@ public function getForm($data = array(), $loadData = true)
 			return false;
 		}
 
-		$jinput = $app->input;
-
-		/*
-		 * The front end calls this model and uses a_id to avoid id clashes so we need to check for that first.
-		 * The back end uses id so we use that the rest of the time and set it to 0 by default.
-		 */
-		$id = $jinput->get('a_id', $jinput->get('id', 0));
+		$id = (int) $this->getState('article.id');
 
-		// Determine correct permissions to check.
-		if ($id = $this->getState('article.id', $id))
+		// For new articles we load the potential state + associations
+		if ($id == 0 && $formField = $form->getField('catid'))
 		{
-			if ($app->isClient('site'))
-			// Existing record. We can't edit the category in frontend if not edit.state.
-			{
-				if ($id != 0 && (!$user->authorise('core.edit.state', 'com_content.article.' . (int) $id))
-					|| ($id == 0 && !$user->authorise('core.edit.state', 'com_content')))
-				{
-					$form->setFieldAttribute('catid', 'readonly', 'true');
-					$form->setFieldAttribute('catid', 'required', 'false');
-					$form->setFieldAttribute('catid', 'filter', 'unset');
-				}
-			}
-		}
-		else
-		{
-			// For new articles we load the potential state + associations
-			if ($formField = $form->getField('catid'))
-			{
-				$assignedCatids = (int) ($data['catid'] ?? $form->getValue('catid'));
+			$assignedCatids = $data['catid'] ?? $form->getValue('catid');
 
-				$assignedCatids = is_array($assignedCatids)
-					? (int) reset($assignedCatids)
-					: (int) $assignedCatids;
+			$assignedCatids = is_array($assignedCatids)
+				? (int) reset($assignedCatids)
+				: (int) $assignedCatids;
+
+			// Try to get the category from the category field
+			if (empty($assignedCatids))
+			{
+				$assignedCatids = $formField->getAttribute('default', null);
 
-				// Try to get the category from the category field
-				if (empty($assignedCatids))
+				if (!$assignedCatids)
 				{
-					$assignedCatids = $formField->getAttribute('default', null);
+					// Choose the first category available
+					$catOptions = $formField->options;
 
-					if (!$assignedCatids)
+					if ($catOptions && !empty($catOptions[0]->value))
 					{
-						// Choose the first category available
-						$catOptions = $formField->options;
-
-						if ($catOptions && !empty($catOptions[0]->value))
-						{
-							$assignedCatids = (int) $catOptions[0]->value;
-						}
+						$assignedCatids = (int) $catOptions[0]->value;
 					}
 				}
-
-				// Activate the reload of the form when category is changed
-				$form->setFieldAttribute('catid', 'refresh-enabled', true);
-				$form->setFieldAttribute('catid', 'refresh-cat-id', $assignedCatids);
-				$form->setFieldAttribute('catid', 'refresh-section', 'article');
 			}
+
+			// Activate the reload of the form when category is changed
+			$form->setFieldAttribute('catid', 'refresh-enabled', true);
+			$form->setFieldAttribute('catid', 'refresh-cat-id', $assignedCatids);
+			$form->setFieldAttribute('catid', 'refresh-section', 'article');
 		}
 
 		// Check for existing article.
@@ -581,24 +553,6 @@ public function getForm($data = array(), $loadData = true)
 			$form->setFieldAttribute('state', 'filter', 'unset');
 		}
 
-		// Prevent messing with article language and category when editing existing article with associations
-		$assoc = Associations::isEnabled();
-
-		// Check if article is associated
-		if ($this->getState('article.id') && $app->isClient('site') && $assoc)
-		{
-			$associations = Associations::getAssociations('com_content', '#__content', 'com_content.item', $id);
-
-			// Make fields read only
-			if (!empty($associations))
-			{
-				$form->setFieldAttribute('language', 'readonly', 'true');
-				$form->setFieldAttribute('catid', 'readonly', 'true');
-				$form->setFieldAttribute('language', 'filter', 'unset');
-				$form->setFieldAttribute('catid', 'filter', 'unset');
-			}
-		}
-
 		return $form;
 	}
 
diff --git a/components/com_content/src/Model/FormModel.php b/components/com_content/src/Model/FormModel.php
index 9172510f446aa..b63bb2d0ad4d3 100644
--- a/components/com_content/src/Model/FormModel.php
+++ b/components/com_content/src/Model/FormModel.php
@@ -17,6 +17,7 @@
 use Joomla\CMS\Language\Associations;
 use Joomla\CMS\Language\Multilanguage;
 use Joomla\CMS\Object\CMSObject;
+use Joomla\CMS\Table\Table;
 use Joomla\Registry\Registry;
 use Joomla\Utilities\ArrayHelper;
 
@@ -201,6 +202,55 @@ public function save($data)
 		return parent::save($data);
 	}
 
+	/**
+	 * Method to get the record form.
+	 *
+	 * @param   array    $data      Data for the form.
+	 * @param   boolean  $loadData  True if the form is to load its own data (default case), false if not.
+	 *
+	 * @return  Form|boolean  A Form object on success, false on failure
+	 *
+	 * @since   1.6
+	 */
+	public function getForm($data = [], $loadData = true)
+	{
+		$form = parent::getForm($data, $loadData);
+
+		if (empty($form))
+		{
+			return false;
+		}
+
+		$user = Factory::getApplication()->getIdentity();
+
+		$id = (int) $this->getState('article.id');
+
+		// Existing record. We can't edit the category in frontend if not edit.state.
+		if ($id > 0 && !$user->authorise('core.edit.state', 'com_content.article.' . $id))
+		{
+			$form->setFieldAttribute('catid', 'readonly', 'true');
+			$form->setFieldAttribute('catid', 'required', 'false');
+			$form->setFieldAttribute('catid', 'filter', 'unset');
+		}
+
+		// Prevent messing with article language and category when editing existing article with associations
+		if ($this->getState('article.id') && Associations::isEnabled())
+		{
+			$associations = Associations::getAssociations('com_content', '#__content', 'com_content.item', $id);
+
+			// Make fields read only
+			if (!empty($associations))
+			{
+				$form->setFieldAttribute('language', 'readonly', 'true');
+				$form->setFieldAttribute('catid', 'readonly', 'true');
+				$form->setFieldAttribute('language', 'filter', 'unset');
+				$form->setFieldAttribute('catid', 'filter', 'unset');
+			}
+		}
+
+		return $form;
+	}
+
 	/**
 	 * Allows preprocessing of the JForm object.
 	 *
@@ -228,7 +278,7 @@ protected function preprocessForm(Form $form, $data, $group = 'content')
 			$form->setFieldAttribute('language', 'default', '*');
 		}
 
-		return parent::preprocessForm($form, $data, $group);
+		parent::preprocessForm($form, $data, $group);
 	}
 
 	/**