Laravel belongsTo not returning any values

I have a class called Dbc which has 'links' attached to it called DbcLink. Each link had a 'type' (DbcLinkType)

I'm returning the links attached to the Dbc fine

 class Dbc extends Model
   {
    use HasFactory;

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

    public function links($filter = NULL)
    {
        return $this->hasMany(DBCLink::class);
    }
   }

$social = $dbc->links()->first();
dd($social);

but when I try and get the 'link type from those links it returns an empty list

class DbcLink extends Model
 {
    use HasFactory;

    public function dbc()
    {
        return $this->belongsTo(Dbc::class);
    }

    public function link_type()
    {
        return $this->belongsTo(DbcLinkType::class);
    }
 }

$social = $dbc->links()->first();
dd($social->link_type()->get());

dbc_links table

dbc_link_types table

Any suggestions as to why its returning an empty list?