If you make an attribute Option List and Select Options Multiple Values is checked it does not have the label built so you can click the words like ConcreteCMS 8 did.
I fixed it by changing the following. I assume my fix would not work correctly in all cases.
\concrete\attributes\select\form.php
Line 20 was
<label class="form-check-label">
<?=$opt->getSelectAttributeOptionDisplayValue()?>
</label>
Changed to
<?= $form->label($view->field('atSelectOptionValue') . '_' . $opt->getSelectAttributeOptionID(), $opt->getSelectAttributeOptionDisplayValue(), ['class' => 'form-check-label'])?>