"No files for wrapper" error

[blacktek]

Hello,
in our development environment we're experiencing some random "No files for wrapper" for the ajax requests
https:///quickdevbar/index/ajax?_=1734367183135 (return a 202 HTTP return code)

After some debug, we've noticed that the problem starts with the execute method in vendor/vpietri/adm-quickdevbar/Controller/Index/Ajax.php

try {
$this->qdbHelperRegister->loadDataFromFile();

        $this->_view->loadLayout('quickdevbar');
        $output = $this->_view->getLayout()->getBlock('quick.dev.maintabs')
            //->setNeedHtmlContent(true)
            ->toHtml();
    } catch (\Exception $e) {
        $output = $e->getMessage();
        $resultRaw->setStatusHeader(
            \Laminas\Http\Response::STATUS_CODE_202,
            \Laminas\Http\AbstractMessage::VERSION_11,
            'QDB Error'
        );
    }

if we use
$this->qdbHelperRegister->loadDataFromFile(true);
it works; the function is defined like this:
public function loadDataFromFile($ajax = false)
{
$wrapperContent = $this->qdbHelper->getWrapperContent($ajax);
$this->setRegisteredData($wrapperContent);
$this->pullDataFromService = false;
}

the stack trace for the error is

No files for wrapper---#0 /var/www/html/vendor/vpietri/adm-quickdevbar/Helper/Register.php(70): ADM\QuickDevBar\Helper\Data->getWrapperContent(false)
#1 /var/www/html/vendor/vpietri/adm-quickdevbar/Controller/Index/Ajax.php(34): ADM\QuickDevBar\Helper\Register->loadDataFromFile()
#2 /var/www/html/vendor/magento/framework/Interception/Interceptor.php(58): ADM\QuickDevBar\Controller\Index\Ajax->execute()
#3 /var/www/html/vendor/magento/framework/Interception/Interceptor.php(138): ADM\QuickDevBar\Controller\Index\Ajax\Interceptor->___callParent('execute', Array)
#4 /var/www/html/vendor/magento/framework/Interception/Interceptor.php(153): ADM\QuickDevBar\Controller\Index\Ajax\Interceptor->Magento\Framework\Interception{closure}()
#5 /var/www/html/generated/code/ADM/QuickDevBar/Controller/Index/Ajax/Interceptor.php(23): ADM\QuickDevBar\Controller\Index\Ajax\Interceptor->___callPlugins('execute', Array, Array)
#6 /var/www/html/vendor/magento/framework/App/Action/Action.php(111): ADM\QuickDevBar\Controller\Index\Ajax\Interceptor->execute()
#7 /var/www/html/vendor/vpietri/adm-quickdevbar/Controller/Index.php(54): Magento\Framework\App\Action\Action->dispatch(Object(Magento\Framework\App\Request\Http))
#8 /var/www/html/vendor/vpietri/adm-quickdevbar/Controller/Index/Ajax.php(66): ADM\QuickDevBar\Controller\Index->dispatch(Object(Magento\Framework\App\Request\Http))
#9 /var/www/html/vendor/magento/framework/Interception/Interceptor.php(58): ADM\QuickDevBar\Controller\Index\Ajax->dispatch(Object(Magento\Framework\App\Request\Http))
#10 /var/www/html/vendor/magento/framework/Interception/Interceptor.php(138): ADM\QuickDevBar\Controller\Index\Ajax\Interceptor->___callParent('dispatch', Array)
#11 /var/www/html/vendor/magento/framework/Interception/Interceptor.php(153): ADM\QuickDevBar\Controller\Index\Ajax\Interceptor->Magento\Framework\Interception{closure}(Object(Magento\Framework\App\Request\Http))
#12 /var/www/html/generated/code/ADM/QuickDevBar/Controller/Index/Ajax/Interceptor.php(32): ADM\QuickDevBar\Controller\Index\Ajax\Interceptor->___callPlugins('dispatch', Array, Array)
#13 /var/www/html/vendor/magento/framework/App/FrontController.php(245): ADM\QuickDevBar\Controller\Index\Ajax\Interceptor->dispatch(Object(Magento\Framework\App\Request\Http))
#14 /var/www/html/vendor/magento/framework/App/FrontController.php(212): Magento\Framework\App\FrontController->getActionResponse(Object(ADM\QuickDevBar\Controller\Index\Ajax\Interceptor), Object(Magento\Framework\App\Request\Http))
#15 /var/www/html/vendor/magento/framework/App/FrontController.php(147): Magento\Framework\App\FrontController->processRequest(Object(Magento\Framework\App\Request\Http), Object(ADM\QuickDevBar\Controller\Index\Ajax\Interceptor))
#16 /var/www/html/vendor/magento/framework/Interception/Interceptor.php(58): Magento\Framework\App\FrontController->dispatch(Object(Magento\Framework\App\Request\Http))
#17 /var/www/html/vendor/magento/framework/Interception/Interceptor.php(138): Magento\Framework\App\FrontController\Interceptor->___callParent('dispatch', Array)
#18 /var/www/html/vendor/magento/module-store/App/FrontController/Plugin/RequestPreprocessor.php(99): Magento\Framework\App\FrontController\Interceptor->Magento\Framework\Interception{closure}(Object(Magento\Framework\App\Request\Http))
#19 /var/www/html/vendor/magento/framework/Interception/Interceptor.php(135): Magento\Store\App\FrontController\Plugin\RequestPreprocessor->aroundDispatch(Object(Magento\Framework\App\FrontController\Interceptor), Object(Closure), Object(Magento\Framework\App\Request\Http))
#20 /var/www/html/vendor/amasty/module-push-notifications/Plugin/Action.php(84): Magento\Framework\App\FrontController\Interceptor->Magento\Framework\Interception{closure}(Object(Magento\Framework\App\Request\Http))
#21 /var/www/html/vendor/magento/framework/Interception/Interceptor.php(135): Amasty\PushNotifications\Plugin\Action->aroundDispatch(Object(Magento\Framework\App\FrontController\Interceptor), Object(Closure), Object(Magento\Framework\App\Request\Http))
#22 /var/www/html/vendor/magento/module-page-cache/Model/App/FrontController/BuiltinPlugin.php(75): Magento\Framework\App\FrontController\Interceptor->Magento\Framework\Interception{closure}(Object(Magento\Framework\App\Request\Http))
#23 /var/www/html/vendor/magento/framework/Interception/Interceptor.php(135): Magento\PageCache\Model\App\FrontController\BuiltinPlugin->aroundDispatch(Object(Magento\Framework\App\FrontController\Interceptor), Object(Closure), Object(Magento\Framework\App\Request\Http))
#24 /var/www/html/vendor/magento/framework/Interception/Interceptor.php(153): Magento\Framework\App\FrontController\Interceptor->Magento\Framework\Interception{closure}(Object(Magento\Framework\App\Request\Http))
#25 /var/www/html/generated/code/Magento/Framework/App/FrontController/Interceptor.php(23): Magento\Framework\App\FrontController\Interceptor->___callPlugins('dispatch', Array, NULL)
#26 /var/www/html/vendor/magento/framework/App/Http.php(116): Magento\Framework\App\FrontController\Interceptor->dispatch(Object(Magento\Framework\App\Request\Http))
#27 /var/www/html/generated/code/Magento/Framework/App/Http/Interceptor.php(23): Magento\Framework\App\Http->launch()
#28 /var/www/html/vendor/magento/framework/App/Bootstrap.php(264): Magento\Framework\App\Http\Interceptor->launch()
#29 /var/www/html/pub/index.php(144): Magento\Framework\App\Bootstrap->run(Object(Magento\Framework\App\Http\Interceptor))
#30 {main}

[blacktek]

@vpietri
this error seems related to frontend FPC (redis FPC too). If we add a random string to the page URL it disappears