gmw_ajax_fix.php

<?php

/**
 * Enqueue GMW scripts outside the shortcode during page load.
 *
 * @return [type] [description]
 */
function gmw_custom_load_sctips() {

	GMW_Maps_API::load_scripts();
}

add_action( 'wp_footer', 'gmw_custom_load_sctips' );

/**
 * Generate and render the map during AJAX request.
 *
 * @param  [type] $map_args [description]
 * @param  [type] $gmw      [description]
 *
 * @return [type]           [description]
 */
function gmw_custom_load_map_via_ajax( $map_args, $gmw ) {

	if ( 3 !== absint( $gmw['ID'] ) ) {
		return $map_args;
	}

	// Prepare it for JS.
	$map_args = wp_json_encode( $map_args );
	?>
    <script>
        jQuery(window).ready(function () {

            var mapArgs = <?php echo $map_args; ?>;
            var mapId = <?php echo $gmw['ID']; ?>;

            // generate map if not exists
            if (typeof GMW_Maps[mapId] == 'undefined') {

                // generate map object when ajax is triggered.
                GMW_Maps[mapId] = new GMW_Map(mapArgs.settings, mapArgs.map_options, mapArgs.form);

                // render the map.
                GMW_Maps[mapId].render(mapArgs.locations, mapArgs.user_location);

                // Otherwise, update an existing map.
            } else {
                GMW_Maps[mapId].update(mapArgs.locations, mapArgs.user_location);
            }
        });
    </script>
	<?php
	return $map_args;
}

add_filter( 'gmw_map_element', 'gmw_custom_load_map_via_ajax', 50, 2 );