gotygota

Fantastic that worked! Thank you very much!

In case someone as the same issue, removing the parent function is not necessary. The final code snippet I used was the following:

add_filter('the_password_form', 'new_password_form', 11);

function new_password_form ()   {
    global $post;    
    $label = 'pwbox-'.( empty( $post->ID ) ? rand() : $post->ID );    
    $o = '<form action="' . esc_url( home_url( 'wp-login.php?action=postpass', 'login_post' ) ) . '" method="post">    <div class="d-block mb-3">' . __( "THE NEW TEXT", "wp-bootstrap-starter" ) . '</div>    <div class="form-group form-inline"><label for="' . $label . '" class="mr-2">' . __( "TEXT BEFORE PASSWORD BOX", "wp-bootstrap-starter" ) . ' </label><input name="post_password" id="' . $label . '" type="password" size="20" maxlength="20" class="form-control mr-2" /> <input type="submit" name="Submit" value="' . esc_attr__( "BUTTON TEXT", "wp-bootstrap-starter" ) . '" class="btn btn-primary"/></div>    </form><p> SOME EXTRA TEXT UNDER THE FORM </a>.</p> ';    
    return $o;
}

Thanks again for the help!