Non-uuid foreign key cannot be implemented

Question

I am creating tables in a Postgre database, in the tables I use UUID as the primary key. For that, I executed: CREATE EXTENSION IF NOT EXISTS "uuid-ossp";
So I created the first table with:

DROP TABLE IF EXISTS documentos;
CREATE TABLE IF NOT EXISTS documentos (
  id uuid DEFAULT uuid_generate_v4 (),
  nome VARCHAR (64) NOT NULL,
  ativo INTEGER NOT NULL DEFAULT 1,
  created_at VARCHAR (32),
  updated_at VARCHAR (32),
  UNIQUE(id)
);

The next table should be as follows:

DROP TABLE IF EXISTS diretores;
CREATE TABLE IF NOT EXISTS diretores (
  id uuid DEFAULT uuid_generate_v4 (),
  nome VARCHAR (64) NOT NULL,
  email VARCHAR (64) NOT NULL UNIQUE,
  ativo INTEGER NOT NULL DEFAULT 1,
  created_at VARCHAR (32),
  updated_at VARCHAR (32),
  inicio VARCHAR (12),
  documento VARCHAR (64),
  documento_id INTEGER REFERENCES documentos(id) MATCH SIMPLE
    ON UPDATE NO ACTION ON DELETE NO ACTION,
    UNIQUE(id)
);

But when running the above SQL error is returned to me: foreign key constraint "diretores_documento_id_fkey" cannot be implemented.
Why this key cannot be implemented, since I have declared that it will be unique and the extension has already been declared?