InputGroupTrait : Error with InputGroupTrait when a field (with complex addons options) have a validation error

[MaximeOh]

I have an error with a Formless Model when my field have a validation error.

Important thing, this issue is present only when my field have addon and addons options with class property filled.

I used CakePhp 5.1.6 and Bootstrap-ui 5.1.1 (the last version)

// no bug here
$this->Form->control('paperWidth', ['class' => 'form-control', 'append' => ['mm']]);

// no bug here too
$this->Form->control('paperWidth', ['class' => 'form-control', 'append' => ['mm', ['size' => 'lg']]]);

// bug here
$this->Form->control('paperWidth', ['class' => 'form-control', 'append' => ['mm', ['size' => 'lg', 'class' => 'input-group-with-unit']]]);