Rails model where clause for has_many_through relation - ruby-on-rails

Question

I have the following model setup:
class Project < ApplicationRecord
has_many :assignments
has_many :participents, through: :assignments
end
class Participent < ApplicationRecord
devise :database_authenticatable, :registerable,
:recoverable, :rememberable, :validatable
has_many :assignments
has_many :projects, through: :assignments
end
class Client < ApplicationRecord
devise :database_authenticatable, :registerable,
:recoverable, :rememberable, :validatable
has_many :assignments
has_many :projects, through: :assignments
end
class Assignment < ApplicationRecord
# belongs_to :client
belongs_to :participent
end
In my ParticipentsController I want to find projects that I did not participate to. But my code always returns all projects:
me = current_participent #current logged in user
Project.joins(:participents).where.not(participents: {id: me.id})
Can anyone point me to my mistake?
EDIT: me.id is not nil, it's a number object.
I also can reproduce this in rails console. For more context I post my schema.rb:
ActiveRecord::Schema.define(version: 2019_09_03_173831) do
create_table "articles", force: :cascade do |t|
t.string "title"
t.text "text"
t.datetime "created_at", precision: 6, null: false
t.datetime "updated_at", precision: 6, null: false
end
create_table "assignments", force: :cascade do |t|
t.integer "client_id"
t.integer "participent_id"
t.integer "project_id"
t.datetime "created_at", precision: 6, null: false
t.datetime "updated_at", precision: 6, null: false
t.index ["client_id"], name: "index_assignments_on_client_id"
t.index ["participent_id"], name: "index_assignments_on_participent_id"
end
create_table "clients", force: :cascade do |t|
t.string "email", default: "", null: false
t.string "encrypted_password", default: "", null: false
t.string "reset_password_token"
t.datetime "reset_password_sent_at"
t.datetime "remember_created_at"
t.datetime "created_at", precision: 6, null: false
t.datetime "updated_at", precision: 6, null: false
t.index ["email"], name: "index_clients_on_email", unique: true
t.index ["reset_password_token"], name: "index_clients_on_reset_password_token", unique: true
end
create_table "participents", force: :cascade do |t|
t.string "name"
t.datetime "created_at", precision: 6, null: false
t.datetime "updated_at", precision: 6, null: false
t.string "email", default: "", null: false
t.string "encrypted_password", default: "", null: false
t.string "reset_password_token"
t.datetime "reset_password_sent_at"
t.datetime "remember_created_at"
t.index ["email"], name: "index_participents_on_email", unique: true
t.index ["reset_password_token"], name: "index_participents_on_reset_password_token", unique: true
end
create_table "projects", force: :cascade do |t|
t.string "title"
t.integer "client_id"
t.datetime "published_at"
t.datetime "created_at", precision: 6, null: false
t.datetime "updated_at", precision: 6, null: false
t.index ["client_id"], name: "index_projects_on_client_id"
end
add_foreign_key "projects", "clients"
end
SOLUTION: https://stackoverflow.com/a/58001556/890270