PgSslMode::Allow doesn't connecto to a SSL mode require server

[eyyyyyyy3]

I have a application, that lets you select the desired ssl mode.

use_tls: bool,

//https://docs.rs/sqlx/latest/sqlx/postgres/enum.PgSslMode.html
let connect_options = PgConnectOptions::new()
    .host(host)
    .port(port.parse().unwrap_or(5432))
    .username(user)
    .password(password)
    .database(database)
    .ssl_mode(match use_tls {
        true => PgSslMode::Require,
        false => PgSslMode::Allow,
    });

match postgres::PgPool::connect_with(connect_options).await {
    Ok(x) => {
        drop(connection.0.write().await.replace(x));
        return Ok(format!("SUCCESS"));
    }
    Err(_) => return Err(format!("Couldn't connect to the database!")),
}

In case of true we will require a ssl mode and in case of false we'll try with no ssl mode but fall back to ssl if we can not connect otherwise.

I am using a Postgres15 database that is hosted on fl0.com.
The database has SSL mode set to require.

When trying to connecto to it with PgSslMode::Require it works perfectly fine but when trying to use PgSslMode::Allow it doesn't connect.

My expectations: When i try to establish a connection to s SSL require db with the ssl_mode set to PgSslMode::Allow it will try to connect to it 2 times. First without any SSL and if that fails it will try a SSl connection.

The code doesn't work as expected, neither on macOS nor on Windows.

I am using the following sqlx features (Cargo.toml):

sqlx = { version = "0.7.3", features = [
"postgres",
"runtime-tokio",
"tls-native-tls",
]

And I have also tried it with tls-rustls with the same results.

Is this a bug or am I expecting something that isn't true?