diff --git a/Build/phpstan/phpstan-baseline.neon b/Build/phpstan/phpstan-baseline.neon
index 70edd0496911..08d2de5f7377 100644
--- a/Build/phpstan/phpstan-baseline.neon
+++ b/Build/phpstan/phpstan-baseline.neon
@@ -75,11 +75,6 @@ parameters:
 			count: 1
 			path: ../../typo3/sysext/backend/Classes/Controller/File/ThumbnailController.php
 
-		-
-			message: "#^Call to function is_array\\(\\) with string\\|null will always evaluate to false\\.$#"
-			count: 1
-			path: ../../typo3/sysext/backend/Classes/Controller/FormInlineAjaxController.php
-
 		-
 			message: "#^Parameter \\#1 \\.\\.\\.\\$expressions of method TYPO3\\\\CMS\\\\Core\\\\Database\\\\Query\\\\Expression\\\\ExpressionBuilder\\:\\:orX\\(\\) expects string, TYPO3\\\\CMS\\\\Core\\\\Database\\\\Query\\\\Expression\\\\CompositeExpression given\\.$#"
 			count: 1
diff --git a/typo3/sysext/backend/Classes/Controller/FormInlineAjaxController.php b/typo3/sysext/backend/Classes/Controller/FormInlineAjaxController.php
index 30bcb6e918d5..41d9a4712bd9 100644
--- a/typo3/sysext/backend/Classes/Controller/FormInlineAjaxController.php
+++ b/typo3/sysext/backend/Classes/Controller/FormInlineAjaxController.php
@@ -355,7 +355,7 @@ public function synchronizeLocalizeAction(ServerRequestInterface $request): Resp
 
                 // Get the name of the field used as foreign selector (if any):
                 $foreignSelector = isset($parentConfig['foreign_selector']) && $parentConfig['foreign_selector'] ? $parentConfig['foreign_selector'] : false;
-                $selectedValue = $foreignSelector ? GeneralUtility::quoteJSvalue($childData['databaseRow'][$foreignSelector]) : null;
+                $selectedValue = $foreignSelector ? $childData['databaseRow'][$foreignSelector] : null;
                 if (is_array($selectedValue)) {
                     $selectedValue = $selectedValue[0];
                 }
diff --git a/typo3/sysext/core/Tests/Acceptance/Application/FormEngine/InlineContentElementLocalizeSynchronizeCest.php b/typo3/sysext/core/Tests/Acceptance/Application/FormEngine/InlineContentElementLocalizeSynchronizeCest.php
new file mode 100644
index 000000000000..95ac666f67d1
--- /dev/null
+++ b/typo3/sysext/core/Tests/Acceptance/Application/FormEngine/InlineContentElementLocalizeSynchronizeCest.php
@@ -0,0 +1,119 @@
+<?php
+
+declare(strict_types=1);
+
+/*
+ * This file is part of the TYPO3 CMS project.
+ *
+ * It is free software; you can redistribute it and/or modify it under
+ * the terms of the GNU General Public License, either version 2
+ * of the License, or any later version.
+ *
+ * For the full copyright and license information, please read the
+ * LICENSE.txt file that was distributed with this source code.
+ *
+ * The TYPO3 project - inspiring people to share!
+ */
+
+namespace TYPO3\CMS\Core\Tests\Acceptance\Application\FormEngine;
+
+use Facebook\WebDriver\Remote\RemoteWebDriver;
+use Facebook\WebDriver\WebDriverBy;
+use TYPO3\CMS\Core\Tests\Acceptance\Support\ApplicationTester;
+use TYPO3\CMS\Core\Tests\Acceptance\Support\Helper\PageTree;
+
+class InlineContentElementLocalizeSynchronizeCest
+{
+    public function _before(ApplicationTester $I, PageTree $pageTree): void
+    {
+        $I->useExistingSession('admin');
+
+        $I->click('Page');
+        $I->waitForElement('svg .nodes .node');
+        $pageTree->openPath(['styleguide TCA demo', 'staticdata']);
+        $I->switchToContentFrame();
+        $I->waitForText('staticdata', 20);
+    }
+
+    public function addingResourceToDefaultLangPageAddResourceToLocalizedPage(ApplicationTester $I): void
+    {
+        // Add a content element type images and localize it
+        $I->click('.module-body td[data-language-uid="0"] span[data-identifier="actions-add"]');
+        $I->switchToWindow();
+        $I->waitForText('Images Only');
+        $I->click('Images Only');
+        $I->switchToContentFrame();
+        $I->waitForText('Create new Page Content on page "staticdata"', 3, 'h1');
+        $I->click('Images');
+        // Inline add record in Resources tab
+        $I->click('Images');
+        $I->click('span[data-identifier="actions-insert-record"]', 'div.active');
+        $I->switchToWindow();
+        $I->switchToIFrame('modal_frame');
+        // Find page 'styleguide' in page tree of modal and click it
+        $context = $I->executeInSelenium(function (RemoteWebDriver $webdriver) {
+            $context = $webdriver->findElement(WebDriverBy::cssSelector('div.element-browser-main-sidebar'));
+            return $context->findElement(WebDriverBy::xpath('//*[text()=\'styleguide\']/..'));
+        });
+        // Add an image, closes modal again
+        $context->findElement(WebDriverBy::cssSelector('text.node-name'))->click();
+        $I->waitForElementVisible('#typo3-filelist a[data-file-name="telephone_box.jpg"]');
+        $I->click('#typo3-filelist a[data-file-name="telephone_box.jpg"]');
+        // Save, go back to page
+        $I->switchToWindow();
+        $I->switchToContentFrame();
+        $I->click('.module-docheader a[title="Close"]');
+        $I->switchToWindow();
+        $I->waitForText('Save and close');
+        $I->click('Save and close');
+        // Switch to "All languages" view and localize content element
+        $I->switchToContentFrame();
+        $I->waitForElementVisible('select[name=actionMenu]');
+        $I->selectOption('select[name=actionMenu]', 'Languages');
+        $I->waitForElementVisible('select[name=languageMenu]');
+        $I->selectOption('select[name=languageMenu]', 'All languages');
+        $I->waitForText('Translate');
+        $I->click('Translate');
+        $I->switchToWindow();
+        $I->waitForText('Localize page "staticdata - language 1" into styleguide demo language danish');
+        $I->click('span[data-identifier="actions-localize"]');
+        $I->click('Next');
+        $I->waitForText('Normal');
+        $I->click('Next');
+        $I->switchToContentFrame();
+        $I->waitForText('(copy 1)');
+        // Edit default language content element again and add another image
+        $I->click('.module-body td[data-language-uid="0"] span[data-identifier="actions-open"]');
+        $I->waitForText('Edit Page Content on page "staticdata"', 3, 'h1');
+        $I->click('Images');
+        $I->click('span[data-identifier="actions-insert-record"]', 'div.active');
+        $I->switchToWindow();
+        $I->switchToIFrame('modal_frame');
+        // Find page 'styleguide' in page tree of modal and click it
+        $context = $I->executeInSelenium(function (RemoteWebDriver $webdriver) {
+            $context = $webdriver->findElement(WebDriverBy::cssSelector('div.element-browser-main-sidebar'));
+            return $context->findElement(WebDriverBy::xpath('//*[text()=\'styleguide\']/..'));
+        });
+        // Add an image, closes modal again
+        $context->findElement(WebDriverBy::cssSelector('text.node-name'))->click();
+        $I->waitForElementVisible('#typo3-filelist a[data-file-name="underground.jpg"]');
+        $I->click('#typo3-filelist a[data-file-name="underground.jpg"]');
+        // Save, go back to page
+        $I->switchToWindow();
+        $I->switchToContentFrame();
+        $I->click('.module-docheader a[title="Close"]');
+        $I->switchToWindow();
+        $I->waitForText('Save and close');
+        $I->click('Save and close');
+        // Open the localized element and see that the second image can be synchronized
+        $I->switchToContentFrame();
+        $I->waitForText('(copy 1)');
+        $I->click('.module-body td[data-language-uid="1"] span[data-identifier="actions-open"]');
+        $I->waitForText('Edit Page Content " (copy 1)" on page "staticdata"', 3, 'h1');
+        $I->click('Images');
+        $I->waitForText('underground.jpg');
+        $I->click('span[data-identifier="actions-document-localize"]');
+        // Synchronized image has been opened
+        $I->waitForText('Image Metadata');
+    }
+}
diff --git a/typo3/sysext/core/Tests/Acceptance/Application/FormEngine/InlinePagesLocalizeResourceCest.php b/typo3/sysext/core/Tests/Acceptance/Application/FormEngine/InlinePagesLocalizeResourceCest.php
new file mode 100644
index 000000000000..511b5413f8e1
--- /dev/null
+++ b/typo3/sysext/core/Tests/Acceptance/Application/FormEngine/InlinePagesLocalizeResourceCest.php
@@ -0,0 +1,72 @@
+<?php
+
+declare(strict_types=1);
+
+/*
+ * This file is part of the TYPO3 CMS project.
+ *
+ * It is free software; you can redistribute it and/or modify it under
+ * the terms of the GNU General Public License, either version 2
+ * of the License, or any later version.
+ *
+ * For the full copyright and license information, please read the
+ * LICENSE.txt file that was distributed with this source code.
+ *
+ * The TYPO3 project - inspiring people to share!
+ */
+
+namespace TYPO3\CMS\Core\Tests\Acceptance\Application\FormEngine;
+
+use Facebook\WebDriver\Remote\RemoteWebDriver;
+use Facebook\WebDriver\WebDriverBy;
+use TYPO3\CMS\Core\Tests\Acceptance\Support\ApplicationTester;
+use TYPO3\CMS\Core\Tests\Acceptance\Support\Helper\PageTree;
+
+class InlinePagesLocalizeResourceCest
+{
+    public function _before(ApplicationTester $I, PageTree $pageTree): void
+    {
+        $I->useExistingSession('admin');
+
+        $I->click('List');
+        $I->waitForElement('svg .nodes .node');
+        $pageTree->openPath(['styleguide TCA demo', 'staticdata']);
+        $I->switchToContentFrame();
+        $I->waitForText('staticdata', 20);
+    }
+
+    public function addingResourceToDefaultLangPageAddResourceToLocalizedPage(ApplicationTester $I): void
+    {
+        // Add an image to media field of default lang page
+        $I->click('.module-docheader a[title="Edit page properties"]');
+        $I->waitForText('Edit Page "staticdata"', 3, 'h1');
+        // Inline add record in Resources tab
+        $I->click('Resources');
+        $I->click('span[data-identifier="actions-insert-record"]', 'div.active');
+        $I->switchToWindow();
+        $I->switchToIFrame('modal_frame');
+        // Find page 'styleguide' in page tree of modal and click it
+        $context = $I->executeInSelenium(function (RemoteWebDriver $webdriver) {
+            $context = $webdriver->findElement(WebDriverBy::cssSelector('div.element-browser-main-sidebar'));
+            return $context->findElement(WebDriverBy::xpath('//*[text()=\'styleguide\']/..'));
+        });
+        // Add an image, closes modal again
+        $context->findElement(WebDriverBy::cssSelector('text.node-name'))->click();
+        $I->waitForElementVisible('#typo3-filelist a[data-file-name="telephone_box.jpg"]');
+        $I->click('#typo3-filelist a[data-file-name="telephone_box.jpg"]');
+        // Save, go back to list
+        $I->switchToWindow();
+        $I->switchToContentFrame();
+        $I->click('.module-docheader a[title="Close"]');
+        $I->switchToWindow();
+        $I->waitForText('Save and close');
+        $I->click('Save and close');
+        // Edit the page translation and see if that resource has been added.
+        $I->switchToContentFrame();
+        $I->waitForText('staticdata - language 1');
+        $I->click('staticdata - language 1');
+        $I->waitForText('Edit Page "staticdata - language 1"', 3, 'h1');
+        $I->click('Resources');
+        $I->see('telephone_box.jpg');
+    }
+}