False positive with multiple nested attributes

[glm4]

Ruby Version: 2.4.1p111 Rails Version: 5.2.0

Having the following relations:

class User
  has_one user_preference
  has_one lifestyle
end

class UserPreference
  belongs_to :user
  has_many :goal_preferences, dependent: :destroy
  has_many :goals, through: :goal_preferences
end

class Lifestyle
  belongs_to :user
  has_many :food_type_lifestyles, dependent: :destroy
  has_many :food_types, through: :food_type_lifestyles
  has_many :activity_type_lifestyles, dependent: :destroy
  has_many :activity_types, through: :activity_type_lifestyles
end

Bullet is warning about N+1 in User => Lifestyle when creating a User. I had the nested attributes for UserPreference before and everything was ok. Then I added Lifestyle and the warning started to appear. Important: It only happens when I send both nested attributes in the params, it turns out that if I send only user_preference_attributes or lifestyle_attributes it won't complain.

Example params:

{
  "user":
  {
    "email": "[email protected]",
    "lifestyle_attributes": {
        "food_type_ids": [1, 2],
        "activity_type_ids": [1, 2, 3]
    },
    "user_preference_attributes": {
    	"goal_ids": [1, 2, 3, 4, 5]
    }
  }
}

Note: All the INSERT queries for the many-to-many relations are executed in a single transaction, so the nested attributes behavior is fine.