Exception on hyva_admin_test/test/form right after install

[OvalMedia]

I installed the admin module and the test module in a Magento 2.4.4 (php 7.4).
When trying to access /hyva_admin_test/test/form/ the page breaks with an exception:

Return value of Hyva\Admin\ViewModel\HyvaForm\FormFieldDefinition::getGroupId() must be of the type string, null returned

…/vendor/hyva-themes/module-magento2-admin/ViewModel/HyvaForm/FormFieldDefinition.php112