Code example that forces the CSS positioning for a specific popup on a specific page

pm_popup_position_fix_script.php

<?php
/**
 * Popup Maker Position Fix
 *
 * Adjusts the position of a specific popup after it opens.
 *
 * Useful when a theme or other pluging messes up the popup's default positioning.
 *
 * Usage: Add this code to your theme's functions.php or a custom plugin.
 * - Update the popup ID (10349) to match your popup.
 * - Change the CSS code below to what you need.
 *
 * This script only loads on the post/page slug: singapore-langkawi-twin-centre-escape
 */

/**
 * Output the popup position fix script in the footer.
 * Loads late (priority 500) to ensure it runs after other scripts.
 */
function pm_popup_position_fix_script() {
    // Only load on the specific post(s) or page(s)
	$allowed_slugs = [ 'singapore-langkawi-twin-centre-escape' ]; // Change this to your post/page slug(s)
	$slug = get_post_field( 'post_name', get_queried_object_id() );
	if ( ! in_array( $slug, $allowed_slugs ) ) return;
    
    ?>
    <script>
    jQuery(document).ready(function($) {
        /**
         * Function to fix popup position with a delay
         */
        function fixPopupPosition() {
            // Check if popup 10349 is the one that just opened
            if ($('#pum-10349').hasClass('pum-active')) { // Change 10349 to your popup ID
                console.log('Fixing popup 10349 position');
                
                /**
                 * Add a slight delay before applying the positiong we want.
                 * That's so we get last dibs to make sure our position wins!
                 */
                setTimeout(function() {
                    // This is the part that fixes the conflict in the popup positioning.
					// We force the position to the middle of the viewable area.
					// NOTE: Change any of the CSS attributes to what you want.
                    $('#popmake-10349').css({ // Change 10349 to your popup ID
                        'margin': '0',
                        'top': '50%',
                        'left': '50%',
                        'transform': 'translate(-50%, -50%)',
                        'position': 'fixed'
                    });
                }, 50); // 50ms delay; change as needed
            }
        }
        
        /**
         * Listen for the pumAfterOpen event.
         * This fires after any Popup Maker popup finishes opening.
         */
        $(document).on('pumAfterOpen', fixPopupPosition);
        
        /**
         * Listen for the pumBeforeReposition event.
         * This fires before Popup Maker repositions the popup.
         */
        $(document).on('pumBeforeReposition', fixPopupPosition);
    });
    </script>
    <?php
}
add_action( 'wp_footer', 'pm_popup_position_fix_script', 500 );