Why PreparedStatement with setFloat gives a different result (with less precision) from direct INSERT ?

The code below shows the issue:

    Connection conn = createConnection();

/* here works as expected */
    String sql = "INSERT INTO teste values (1, -50.505050)";
    PreparedStatement ps = conn.prepareStatement(sql);
    ps.executeUpdate();

/* below, all values were saved with less precision */
    sql = "INSERT INTO teste values (?, ?)";
    ps = conn.prepareStatement(sql);

    ps.setInt(1, 2);
    ps.setFloat(2, -50.505050f);
    ps.executeUpdate();

    ps.setInt(1, 3);
    ps.setFloat(2, (float) -50.505050);
    ps.executeUpdate();

    ps.setInt(1, 4);
    ps.setFloat(2, Float.valueOf(-50.505050f));
    ps.executeUpdate();

    ps.setInt(1, 5);
    ps.setFloat(2, Float.valueOf("-50.505050"));
    ps.executeUpdate();

// with double works ok, but how? //
    ps.setInt(1, 6);
    ps.setDouble(2, -50.505050);
    ps.executeUpdate();

    ps.close();
    conn.close();

The database is PostgreSQL, with two columns, an id (bigint) and valor (numeric (9,6)).

Here is the output, from pgadmin4.

The only relevant dependency in pom.xml is below:

    <dependency>
        <groupId>org.postgresql</groupId>
        <artifactId>postgresql</artifactId>
        <version>42.2.8</version>
    </dependency>

The script I used for CREATE the table.

CREATE TABLE public.teste
(
    id bigint NOT NULL,
    valor numeric(9,6),
    CONSTRAINT teste_pkey PRIMARY KEY (id)
)
WITH (
    OIDS = FALSE
)
TABLESPACE pg_default;

ALTER TABLE public.teste
    OWNER to postgres;

I am using Java 11.