Unable to use typed variables in a cell

How are you passing the variable to the view?

As you can read here, those are made available automatically to the view file, because I'm using controlled cells

---

View Cells must return a string not an int.

As far as I can see, the Cell is returning a string, because it's returning the content of just_a_test.php.
But for the sake of the conversation, here is the modified version, returning the same error, which is:

Code:

Undefined variable $typedVariable

Code:

JustATestCell.php

PHP Code:

<?php

namespace App\Cells;

use CodeIgniter\View\Cells\Cell;

class JustATestCell extends Cell
{
    public string $typedVariable;
} 


Code:

just_a_test.php

PHP Code:

<div>
    <?= $typedVariable; ?>
</div> 


Code:

main view file

PHP Code:

<?=    view_cell('JustATestCell', [
            'typedVariable' => 'test'
        ]);
    ?>