TYPO3 Core

*Versions of relevant Components:

Typo3-Version: 12.4.3
PHP Version: 8.1
CMS-Form: 12.4.3

*Steps to Reproduce:

Step 1: Design a form with variants and introduce a condition basing on value of a form element

Example with such a constellation is attached -> so feel free to try this.

Step 2: Try to include this form on an arbitrary page and call it in the frontend

*Result:

An exception is thrown, saying that the array key is not defined although it should be:

(1/1) #1476107295 TYPO3\CMS\Core\Error\Exception
PHP Warning: Undefined array key "checkbox-1" in /var/www/html/vendor/symfony/expression-language/Node/GetAttrNode.php line 133