Rails and postgresql not dialoguing properly on record creation - ruby-on-rails

Question

The following record creation is failing as the data is being misinterpreted by Postgresql
SQL (1.3ms) INSERT INTO "gruppomerceologicos" ("nome", "reparto_id", "created_at", "updated_at") VALUES ($1, $2, $3, $4) RETURNING "id" [["nome", "Salumeria"], ["reparto_id", 1], ["created_at", "2020-03-13 09:24:15.529470"], ["updated_at", "2020-03-13 09:24:15.529470"]]
(0.2ms) ROLLBACK
Completed 500 Internal Server Error in 11ms (ActiveRecord: 2.5ms)
PG::NotNullViolation - ERROR: null value in column "id" violates not-null constraint
DETAIL: Failing row contains (null, Salumeria, 2020-03-13 09:24:15.52947, 2020-03-13 09:24:15.52947, 1).
The row creation is in effect incorrect as PostgreSQL is attempting to handle a record with a nullvalue for id
The controller is standard
#gruppomerceologico = Gruppomerceologico.new(gruppomerceologico_params)
authorize #gruppomerceologico
#gruppomerceologico.save
respond_with(#gruppomerceologico)
The rails debugger does however show that it is attempting to handle a record without an ID at point where error is occuring
#gruppomerceologico
#<Gruppomerceologico id: nil, nome: "Salumeria", created_at: "2020-03-13 08:24:15", updated_at: "2020-03-13 08:24:15", reparto_id: 1>
Postgre has the following data structure
Table "public.gruppomerceologicos"
Column | Type | Modifiers
------------+-----------------------------+-----------
id | integer | not null
nome | character varying |
created_at | timestamp without time zone | not null
updated_at | timestamp without time zone | not null
reparto_id | integer |
Indexes:
"gruppomerceologicos_pkey" PRIMARY KEY, btree (id)
"index_gruppomerceologicos_on_reparto_id" btree (reparto_id) Foreign-key constraints:
"fk_rails_d8a087054a" FOREIGN KEY (reparto_id) REFERENCES repartos(id) Referenced by:
TABLE "materiagrezzas" CONSTRAINT "fk_rails_2b6ca167a0" FOREIGN KEY (gruppomerceologico_id) REFERENCES gruppomerceologicos(id)
Normally Postgre knows it is creating a new record and will thus assign the sequential ID and create the record. But this is not happening. Where is the gap between rails and Postgresql?
The initial migration:
class CreateGruppomerceologicos < ActiveRecord::Migration
def change
create_table :gruppomerceologicos do |t|
t.string :nome
t.timestamps null: false
end
end
end
followed by an update in migration
class AddRepartoToGruppomerceologicos < ActiveRecord::Migration
def change
add_reference :gruppomerceologicos, :reparto, index: true, foreign_key: true
end
end
Update
Double checking with a development server, the \d query for the table returns something completely different:
Table "public.gruppomerceologicos"
Column | Type | Collation | Nullable | Default
------------+-----------------------------+-----------+----------+-------------------------------------------------
id | integer | | not null | nextval('gruppomerceologicos_id_seq'::regclass)
nome | character varying | | |
created_at | timestamp without time zone | | not null |
updated_at | timestamp without time zone | | not null |
where the nextval is obviously in proper play. The two databases were somehow out of synch. As suggested below by #sebastianPalma select nextval('gruppomerceologicos_id_seq'::regclass); will directly reveal the discrepancy.