add_filter page_template more than once in plugin

Why can’t I use add_filter(‘page_template’) more than once in my plugin?
What can I do to solve the problem?

add_filter('page_template', 'my_plugin_login_page');
function my_plugin_login_page($login_template)
{
    $plugin_option = get_option('login_settings');
    $login_page = get_post_field('post_name', $plugin_option ['login-page']) ? get_post_field('post_name', $plugin_option ['login-page']) : 'login';
    if (is_page($login_page)) {
        $login_template = MY_PLUGIN_TEMPLATE . 'login-template.php';
    }
    return $login_template;
}

This function does not work!

add_filter('page_template', 'my_plugin_logout_page');
function my_plugin_logout_page($logout_template)
{
    $plugin_option = get_option('logout_settings');
    $logout_page = get_post_field('post_name', $plugin_option ['logout-page']) ? get_post_field('post_name', $plugin_option ['logout-page']) : 'logout';
    if (is_page($logout_page)) {
        $logout_template = MY_PLUGIN_TEMPLATE . 'logout-template.php';
    }
    return $logout_template;
}