Relationship not reading correctly

I am trying to grab the student that is linked to the contact but I am just getting the contact. Anybody got any idea why.

<?php

namespace App\Models;

use Illuminate\Contracts\Auth\MustVerifyEmail;
use Illuminate\Database\Eloquent\Factories\HasFactory;
use Illuminate\Foundation\Auth\User as Authenticatable;
use Illuminate\Notifications\Notifiable;
use Laravel\Sanctum\HasApiTokens;

class User extends Authenticatable
{
    use HasApiTokens, HasFactory, Notifiable;

    /**
     * The attributes that are mass assignable.
     *
     * @var string[]
     */
    protected $fillable = [
        'category',
        'name',
        'email',
        'password',
    ];

    /**
     * The attributes that should be hidden for serialization.
     *
     * @var array
     */
    protected $hidden = [
        'password',
        'remember_token',
    ];

    /**
     * The attributes that should be cast.
     *
     * @var array
     */
    protected $casts = [
        'email_verified_at' => 'datetime',
    ];

    public function contacts()
    {
        return $this->hasMany(Contact::class);
    }

    public function appointments()
    {
        return $this->hasMany(Appointment::class);
    }
}

<?php

namespace App\Models;

use Illuminate\Database\Eloquent\Factories\HasFactory;
use Illuminate\Database\Eloquent\Model;

class Contact extends Model
{
    use HasFactory;

    protected $fillable = [
        'user_id',
        'forename', 
        'surname', 
        'email',
        'telephone',
        'address',
        'gender',
    ];

    public function students()
    {
        return $this->belongsToMany(Contact::class, 'contact_students');
    }

    public function user()
    {
        return $this->belongsTo(User::class);
    }
}

<?php

namespace App\Models;

use Illuminate\Database\Eloquent\Factories\HasFactory;
use Illuminate\Database\Eloquent\Model;

class Student extends Model
{
    use HasFactory;

    public function contacts()
    {
        return $this->belongsToMany(Contact::class, 'contact_students');
    }

    public function course()
    {
        return $this->belongsToMany(Course::class);
    }

    public function activities()
    {
        return $this->belongsToMany(Activity::class);
    }
}

    public function mount()
    {
        $this->students = Auth::user()->contacts[0]->students;
        dd($this->students);
        $this->activities = Activity::all();
    }

        "id" => 21
        "user_id" => 2
        "forename" => "John"
        "surname" => "Doe"
        "email" => "[email protected]"
        "telephone" => "454325345234"
        "address" => "999 Lets Be Avenue"
        "gender" => "M"
        "created_at" => "2022-05-31 07:12:43"
        "updated_at" => "2022-05-31 07:12:43"
        "pivot_contact_id" => 21