Sign in with credentials from @auth/sveltekit/client doesn't save the session

[ctwhome]

Hi all, I am not sure if this is a bug or I am configuring something wrong.
I have 3 providers, Google, Magic link with Resend, and the old good fashion email and password with Credentials.
The first two work without any problem out of the box, but the credentials do not save the session in the database, only creating the cookie, which disappears after refreshing the page.

Using the signIn() function from @auth/sveltekit/client

async function handleEmailSignIn() {
	const result = await signIn('Credentials', {
		email,
		password
	});
	if (result?.ok) {
		closeModal();
	} else {
		error = 'User authorization failed';
		console.error('User authorization failed', result);
	}
}

My auth.ts file looks like this, leveraging auth.js to save the session in the database with the Postgres adapter. It works perfectly with Google and Resend providers but not with credentials:

export const { handle, signIn, signOut } = SvelteKitAuth({
  trustHost: true,
  adapter: PostgresAdapter(pool),
  secret: process.env.AUTH_SECRET,
  providers: [
    Resend({
      from: "chatdiamond@ctwhome.com",
      name: "Chat Diamond",
    }),
    Google,
    Credentials({
      name: 'Credentials',
      async authorize(credentials) {
        const { email, password } = credentials;
        const result = await pool.query('SELECT * FROM users WHERE email = $1', [email]);
        const user = result.rows[0];
        if (user) {
          const isValid = await bcrypt.compare(password, user.password);
          if (isValid) {
            console.log('User authorized', user);
            return { id: user.id, email: user.email }; 
          }
        }
        console.log('User authorization failed');
        return null;
      }
    })
  ],
  async signIn({ user }) {
    if (user) {
      return true; // THIS TRIGGERS AND RETURNS TRUE, but the session callback doesn't trigger
    }
    return false;
  },
  callbacks: {
    async session({ session, user }) {
      if (user) {
        session.user.id = user.id;
        session.user.email = user.email;
      }
      return session;
    }
  ...
}

Using the strategy database breaks the Resend and Google Providers

session: {
  strategy: "database",
  maxAge: 30 * 24 * 60 * 60, // 30 days
  updateAge: 24 * 60 * 60, // 24 hours
},

Can someone point out what would be wrong?
Many thanks!