问无法调用多态关系的模型

EN

    @foreach ($visits as $visit)
        @if($visit->visitable_type == 'App\User')
        Viewing member profile <a href="/profiles/{{ $visit->user->name }}">{{ $visit->user->name }}</a>
        @endif
        @if($visit->visitable_type == 'App\Thread')
        Viewing thread <a href="/forums/{{ $visit->channel->slug }}/{{ $visit->slug }}/">
        {{ $visit->title }}</a>
        @endif
    @endforeach

$visits = Visit::where('user_id', $user->id)->get();

public function visits()
{
    return $this->morphMany(Visit::class, 'visitable');
}

public function visit()
{
    return $this->morphOne(Visit::class, 'visitable');
}

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

public function thread()
{
    return $this->belongsTo(Thread::class);
}

public function visitable()
{
    return $this->morphTo();
}

public function visits()
{
    return $this->morphMany(Visit::class, 'visitable');
}

public function visit()
{
    return $this->morphOne(Visit::class, 'visitable');
}