Wordpress settings page meta box problem. Works on one site, not on the other - same code, same WP Version

my_plugin_one_functions.php

<?php 
add_action( 'admin_menu' , 'my_plugin_register_plugin_settings', 10 );
function my_plugin_register_plugin_settings() 

    add_menu_page( 
        __( 'My Plugin Title', 'my_plugin' ),
        __( 'My Plugin Menu Text', 'my_plugin' ),
        'manage_options',
        'my-plugin-menu',
        'my_plugin_render_admin_menu_cb',
        'dashicons-location',
        60
    );

    add_submenu_page( 
        'my-plugin-menu',
        __( 'My Plugin Subpage Title', 'my_plugin' ), 
        __( 'Settings', 'my_plugin' ), 
        'manage_options', 
        'my_plugin_settings_page', 
        'my_plugin_settings_page_cb' 
    );
}

//main menu page render callback
function my_plugin_render_admin_menu_cb( ) {
    //not relevant, different page
}

//submenu page render callback
function my_plugin_settings_page_cb() {

    do_action( 'add_meta_boxes', 'my_plugin_settings_page' );

    ?>
 
    <div class="wrap"> 
        <h2><?php _e( 'My Plugin Settings', 'my_plugin' ); ?></h2> 
        <form id="my_plugin_settings_form" method="post" action="admin.php?page=my_plugin_settings_page"> 
            <?php wp_nonce_field( 'closedpostboxes', 'closedpostboxesnonce', false ); ?>
            <?php wp_nonce_field( 'meta-box-order', 'meta-box-order-nonce', false ); ?> 
            <?php wp_nonce_field( 'my_form_nonce', 'my_form_nonce', false ); ?> 
            <div id="poststuff"> 
                <div id="post-body" class="metabox-holder columns-1"> 
                    <div id="postbox-container-1" class="postbox-container">

                        <?php $result = do_meta_boxes( 'my_plugin_settings_page', 'normal', null ); ?>
                        
                    </div>

                </div>
            </div>
        </form>
    </div>
    <?php
}

add_action( 'add_meta_boxes', 'my_plugin_add_settings_meta_boxes' );
function my_plugin_add_settings_meta_boxes() {
    /** Set up Info meta box */
	add_meta_box(
		'my_plugin_meta_box_settings_info',
		__( 'Info', 'my_plugin' ),
		'my_plugin_show_meta_box_info',
		'my_plugin_settings_page',
		'normal',
		'default'
	);

    /** Set up Format Settings meta box */
	add_meta_box(
		'my_plugin_meta_box_settings_format',
		__( 'Output Formatting', 'my_plugin' ), 
		'my_plugin_show_meta_box_settings_format', 
		'my_plugin_settings_page', 
		'normal',
		'default' 
	);	
}

function my_plugin_show_meta_box_info() {
    echo "info box";
}

function my_plugin_show_meta_box_settings_format() {
    echo "format settings box";
}

add_action( 'admin_footer', 'my_plugin_settings_page_footer' );
function my_plugin_settings_page_footer(){
    if ( $_GET['page'] == 'my_plugin_settings_page' ) {
        ?>
        <script type="text/javascript">
            //<![CDATA[
            jQuery(document).ready( function($) {
                // toggle
                $('.if-js-closed').removeClass('if-js-closed').addClass('closed');
                postboxes.add_postbox_toggles( '<?php echo 'my_plugin_settings_page'; ?>' );
            });
            //]]>
        </script>
        <?php
    }
}
?>

my_plugin_two_functions.php

<?php //second plugin file
//this is not removing the metabox like i am expecting it should
//this works on one site, but not the other - using the same code base, same wordpress version
add_action( 'add_meta_boxes', 'my_plugin_do_settings_meta_boxes', 11 );
function my_plugin_do_settings_meta_boxes( $page ) {
    global $my_plugin_status;
    
	if ( $my_plugin_status === true ) {
        if ( $page == 'my_plugin_settings_page' ) {
            remove_meta_box(            
                'my_plugin_meta_box_settings_info',
                'my_plugin_settings_page',
                'default'
            );
        }
    }
} ?>