Laravel retrieving wrong value from database

I'm trying to use a seeder to give, factory created, users the "membro" (member in Portuguese) role. So I have created the roles in a FuncoesSeeder (Funcoes = Functions, or roles in this context) like this:

Funcao::create(['nome' => 'Administrador', 'descricao' => 'Todas as permissões sobre utilizadores e funcionalidades.'])->save();
Funcao::create(['nome' => 'Gestor', 'descricao' => 'Acesso a todas as funcionalidades.'])->save();
Funcao::create(['nome' => 'Membro', 'descricao' => 'Acesso à página principal.'])->save();

Note: The primary key of Funcao is 'nome'.
Then I run UtilizadoresSeeder (Utilizadores = Users):

public function run()
{
    $utilizador = Utilizador::create([
        'nif' => 200000000, 'nome' => 'Name Surname', 'email' => 'name.surname@outlook.pt', 'telemovel' => 912345678,
        'morada' => 'My address', 'codigo_postal' => '2100-123', 'localidade' => 'Ourém',
        'data_admissao' => new DateTime('2000-10-09')
    ]);
    $utilizador->funcoes()->attach('Administrador');
    $utilizador->save();

    $utilizadores = Utilizador::factory(20, new Sequence(fn ($sequence) => ['nif' => 100000000 + $sequence->index]))
        ->create(['password' => null]);

    // Dictionary from Portuguese to English (even though the words are pretty similar)
    // Descrição ("descricao" without special characters) - Description
    // Funcao - Function (in this context is more like a role)
    // funcoes - plural of funcao (functions/roles)
    // Membro - Member
    // Nome - Name
    // utilizador(es) - user(s)
    $funcao = Funcao::find('Membro'); //This works, and it should return a Funcao with ['nome' => 'Membro', 'descricao' => 'Acesso à página principal.']
    echo ('NOME: ' . $funcao->nome . ' - DESCRIÇÃO: ' . $funcao->descricao . "\nJSON: " . $funcao->toJson());
    $funcao->utilizadores()->attach($utilizadores);
}

I don't understand why, but the $funcao->nome returns 0 while $funcao->descricao is correct. I'm using a MySQL database and everything seems fine, plus the line "$utilizador->funcoes()->attach('Administrador');" works perfectly fine. I could probably do it with a foreach, like

foreach ($utilizadores as $utilizador) {
    $utilizador->funcoes()->attach('Membro');
}

But I want to understand why this is happening, is it a database problem?
What am I doing wrong?

Definition of relationships and other stuff that I've double checked:
I've searched for spelling mistakes, but I haven't found any (I might be blind, but I don't think it's the case)
Funcoes table
Funcao model:

<?php

namespace App\Models\Utilizadores;

use Illuminate\Database\Eloquent\Factories\HasFactory;
use Illuminate\Database\Eloquent\Model;

class Funcao extends Model
{
    use HasFactory;

    protected $primaryKey = 'nome';
    protected $table = 'funcoes';
    public $timestamps = false;

    protected $fillable = [
        'nome',
        'descricao'
    ];

    public function utilizadores()
    {
        return $this->belongsToMany(Utilizador::class);
    }
}

Output on powershell

Since you are using a String type attribute as your primary key, you should state it so that Laravel act on that.

By default, for auto-incrementing tables, the ID is assumed to be an integer. By adding:

protected $keyType = 'string';
public $incrementing = false;

to your Funcao Model, this problem should be resolved.