Saving an Association with CakeDC Users

Question

I am using CakeDC Users and as part of the registration I would like the registrant to choose some checkbox values that correspond to another Model in the application. I am able to get the form to load the choices just fine, but I am unable to get it to save to the join table even though I have added all of the associations and accessibilities where it would seem relevant. The form is displaying in a similar way to other areas where I am saving the same type of association with a different model.

TypesTable.php

{
    public function initialize(array $config): void
    {
        //$this->addBehavior('Timestamp');
        $this->setDisplayField('type');
        $this->setPrimaryKey('id');
        $this->belongsToMany('Words');
        $this->belongsToMany('Users');
        $this->belongsTo('Languages', [
            'foreignKey' => 'language_id',
            'joinType' => 'INNER',
        ]);
    }```

UsersTable.php (in the plugin folders)
```class UsersTable extends Table
{
   ...
    public function initialize(array $config): void
    {
        parent::initialize($config);

        $this->setTable('users');
        $this->setDisplayField('username');
        $this->setPrimaryKey('id');
        $this->addBehavior('Timestamp');
        $this->addBehavior('CakeDC/Users.Register');
        $this->addBehavior('CakeDC/Users.Password');
        $this->addBehavior('CakeDC/Users.Social');
        $this->addBehavior('CakeDC/Users.LinkSocial');
        $this->addBehavior('CakeDC/Users.AuthFinder');
        $this->hasMany('SocialAccounts', [
            'foreignKey' => 'user_id',
            'className' => 'CakeDC/Users.SocialAccounts',
        ]);
        $this->hasMany('Types', [
            'foreignKey' => 'user_id', 'targetForeignKey' => 'type_id',
        'joinTable' => 'types_users']);
    }```