Why are all the choice options (Symfony Form) checked by default?

I'm trying to add multiple checkboxes to my form (Symfony Forms, using Symfony 4) by using the ChoiceType. However when loading the page every single checkbox will be selected by default, which I do not want.

The choices are collected in the controller before the form is rendered and send using the $options, like this:

$choices = $tableRepository->getChoices();
$form = $this->createForm(FormType::class, [
    'choices' => $choices,
]);

Here an actual part of the $choices as collected:

array(884) {
  [111]=>
  string(7) "sbi111"
  [113]=>
  string(7) "sbi113"

And then in the form:

->add('names', ChoiceType::class, [
   'label' => 'Choose: ',
   'multiple' => true,
   'expanded' => true,
   'choices' => $options['data']['choices'],
   'required' => false,
])

And like I said this returns the options but all with the checked="checked" attribute. And the strangest part is when I declare the array directly inside the form, so

->add('names', ChoiceType::class, [
   'label' => 'Choose: ',
   'multiple' => true,
   'expanded' => true,
   'choices' => [
       'choice1' => 'value1',
       'choice2' => 'value2',
    ],
   'required' => false,
])

Then it works just fine? So my guess is that issue is with passing the data inside the $options, but I'm not sure what to do here & did not find a single person with the same problem, so if anyone has any idea please let me know. Thanks.