Fatal Error with WP Rocket

Hi,

I found this Fatal Error in debug.log, how can I fix it?

[02-Sep-2024 17:16:01 UTC] PHP Fatal error:  Uncaught Error: Call to a member function save() on bool in /var/www/vhosts/mywebsite.com/httpdocs/wp-content/plugins/woocommerce-wholesale-prices/includes/admin-custom-fields/products/class-wwp-admin-custom-fields-variable-product.php:764
Stack trace:
#0 /var/www/vhosts/mywebsite.com/httpdocs/wp-includes/class-wp-hook.php(326): WWP_Admin_Custom_Fields_Variable_Product->variation_deletion()
#1 /var/www/vhosts/mywebsite.com/httpdocs/wp-includes/class-wp-hook.php(348): WP_Hook->apply_filters()
#2 /var/www/vhosts/mywebsite.com/httpdocs/wp-includes/plugin.php(517): WP_Hook->do_action()
#3 /var/www/vhosts/mywebsite.com/httpdocs/wp-includes/post.php(3534): do_action()
#4 /var/www/vhosts/mywebsite.com/httpdocs/wp-content/plugins/wp-rocket/inc/Engine/Admin/Database/OptimizationProcess.php(83): wp_delete_post()
#5 /var/www/vhosts/mywebsite.com/httpdocs/wp-content/plugins/wp-rocket/inc/classes/dependencies/wp-media/background-processing/wp-background-process.php(315): WP_Rocket\Engine\Admin\Database\OptimizationProcess->task()
#6 /var/www/ in /var/www/vhosts/mywebsite.com/httpdocs/wp-content/plugins/woocommerce-wholesale-prices/includes/admin-custom-fields/products/class-wwp-admin-custom-fields-variable-product.php on line 764