Laravel pluck嵌套关联仅返回部分值，如何获取全部sdoh_category_id？

在Laravel项目中，我通过HouseholdHead模型的sdoh多对多关联，调用pluck('pivot.sdoh_category_id')尝试获取household_id为25的所有sdoh_category_id，但实际仅返回8个值，而数据库的s_d_o_h_category_households关联表中存在15条对应记录。以下是相关代码、模型关联定义及当前返回结果，请求解决获取全部数据的问题：

控制器代码 #

foreach ($households as $household) {
    $chosenSdohCategories = $household->sdoh->pluck('pivot.sdoh_category_id')->toArray();
}

HouseholdHead模型关联定义 #

public function sdoh()
{
    return $this->belongsToMany(SDOH::class, 's_d_o_h_category_households', 'household_head_id', 'sdoh_category_id');
}

SDOH模型关联定义 #

public function sdoh_category()
{
    return $this->hasMany(SDOHCategory::class, 'sdoh_id', 'id');
}

public function household_heads()
{
    return $this->belongsToMany(Household::class, 's_d_o_h_category_households', 'sdoh_category_id', 'household_head_id');
}

当前返回结果 #

array:8 [▼ // resources\views/details-household-modal.blade.php
  0 => 2
  1 => 3
  2 => 5
  3 => 7
  4 => 9
  5 => 12
  6 => 13
  7 => 15
]

内容的提问来源于stack exchange，提问作者Big Brother