Symfony 5 Project: Exception has occurred. ReflectionException: Function include() does not exist – PHP Versions

I get this error no matter what I call in my project. There are no problems without Xdebug. When I turn Xdebug on I always get:

Exception has occurred. ReflectionException: Function include() does not exist

This is the line that gives the error:

$caller = isset($frame['class']) ? new ReflectionMethod($frame['class'], $frame['function']) : new ReflectionFunction($frame['function']);

It’s in ExceptionCaster.php. This is a Symfony file and not one of my own ones.

I use:

Symfony 5.1.8
PHP 8.0.2 (cli) (built: Feb 23 2021 15:14:20) ( NTS )
Copyright (c) The PHP Group
Zend Engine v4.0.2, Copyright (c) Zend Technologies
    with Zend OPcache v8.0.2, Copyright (c), by Zend Technologies
    with Xdebug v3.0.3, Copyright (c) 2002-2021, by Derick Rethans

The route I am calling looks like this:

manage_article:
   path:      /manage_article
   defaults:  { _controller: AppControllerManageArticleController::manageArticleAction }

Is Xdebug not compatible with PHP 8? Or with my version of Symfony? Or what else could be the problem?