PHP Fatal error: Uncaught Error: Call to a member function execute() on bool in

Boa tarde, Quando tento executar o arquivo "criar-turma.php", aparece para mim esse erro: PHP Fatal error: Uncaught Error: Call to a member function execute() on bool in C:\Users\felip\php-pdo-projeto-inicial\src\Infrastructure\Repository\PdoStudentRepository.php:66 Stack trace:

#0 C:\Users\felip\php-pdo-projeto-inicial\src\Infrastructure\Repository\PdoStudentRepository.php(56): Alura\Pdo\Infrastructure\Repository\PdoStudentRepository->insert()

#1 C:\Users\felip\php-pdo-projeto-inicial\criar-turma.php(20): Alura\Pdo\Infrastructure\Repository\PdoStudentRepository->save()

#2 {main} thrown in C:\Users\felip\php-pdo-projeto-inicial\src\Infrastructure\Repository\PdoStudentRepository.php on line 66

os códigos dos arquivos abaixo: criar-turma.php

<?php

use Alura\Pdo\Domain\Model\Student;
use Alura\Pdo\infrastructure\Persistence\ConnectionCreator;
use Alura\Pdo\Infrastructure\Repository\PdoStudentRepository;

require_once 'vendor/autoload.php';

$connection = ConnectionCreator::createConnection();
$studentRepository = new PdoStudentRepository($connection);

$connection->beginTransaction();

$aStudent = new Student(
    null,
    'Nico Steppat',
    new DateTimeimmutable('1985-05-01')
);

$studentRepository->save($aStudent);

$anotherStudent = new Student(
    null,
    'Sergio Lopes',
    new DateTimeimmutable('1985-05-01')
);

$studentRepository->save($anotherStudent);

$connection->commit();

PdoStudentRepository.php

<?php

namespace Alura\Pdo\Infrastructure\Repository;

use Alura\Pdo\Domain\Model\Student;
use Alura\Pdo\Domain\Repository\StudentRepository;
use DateTimeInterface;
use PDO;

class PdoStudentRepository implements StudentRepository
{
    private PDO $connection;

    public function __construct(PDO $connection)
    {
        $this->connection = $connection;
    }

    public function allStudent(): array
    {
        $sqlQuery = 'SELECT * FROM student;';
        $stmt = $this->connection->query($sqlQuery);

        return $this->hydrateStudentList($stmt);
    }

    public function studentBirthAt(DateTimeInterface $birthDate): array
    {
        $sqlQuery = 'SELECT * FROM student WHERE birth_date = ?;';
        $stmt = $this->connection->prepare($sqlQuery);
        $stmt->bindValue(1, $birthDate->format('Y-m-d'));
        $stmt->execute();

        return $this-> hydrateStudentList($stmt);
    }

    private function hydrateStudentList(\PDOStatement $stmt): array
    {
        $studentDataList = $stmt->fetchAll(PDO::FETCH_ASSOC);
        $studentList = [];

        foreach ($studentDataList as $studentData) {
            $studentList[] = new Student(
                $studentData['id'],
                $studentData['name'],
                new \DateTimeImmutable($studentData['birth_date'])
            );
        }

        return $studentList;
    }

    public function save(Student $student): bool
    {
        if($student->id() ===null){
            return $this->insert($student);
        }
        return $this->update($student);
    }

    public function insert(Student $student): bool
    {
        $insertQuery = 'INSERT INTO students (name birth_date) VALUES (:name, :birth_date);';
        $stmt = $this->connection->prepare($insertQuery);

        $success = $stmt->execute([
            ':name' => $student->name(),
            ':birth_date' => $student->birthDate()->format('Y-m-d'),
        ]);

        if ($success){
            $student->defineId($this->connection->lastInsertId());
        }

        return $success;
    }

    public function update(Student $student): bool
    {
        $updateQuery = 'UPDATE students SET name = :name, birth_date = :birth_date WHERE id = :id;';
        $stmt = $this->connection->prepare($updateQuery);
        $stmt->bindValue(':name', $student->name());
        $stmt->bindValue(':birth_date', $student->birthDate()->format('Y-m-d'));
        $stmt->bindValue(':id', $student->id(), PDO::PARAM_INT);

        return $stmt->execute();
    }

    public function remove(Student $student): bool
    {
        $stmt = $this->connection->prepare('DELETE FROM student WHERE id = ?;');
        $stmt->bindValue(1, $student->id(), PDO::PARAM_INT);

        return $stmt->execute();
    }


}