Plugin issue blocking all payments

Hello there,
I have been using your plugin for a while now and it used to work fine. A few days ago it started blocking all payments on my site though and I ended up losing a lot of potential customers because I just found out about it today… I didn’t update anything on the site though so I don’t know why it just stopped working.
Apparently, it’s a bug or incompatibility because it simply closes the WooCommerce PayPal popup window (WC Stripe also didn’t work anymore). I deactivated the plugin now and everything is working again. Could you please check on this? Thank you!

This is the error:

2021-06-01T11:14:43+00:00 CRITICAL Uncaught TypeError: mysqli::real_connect(): Argument #5 ($port) must be of type ?int, string given in /public_html/wp-includes/wp-db.php:2056
Stack trace:
#0 [internal function]: mysqli->real_connect()
#1 /public_html/wp-includes/wp-db.php(2056): mysqli_query()
#2 /wp-includes/wp-db.php(1945): wpdb->_do_query()
#3 /wp-includes/wp-db.php(2695): wpdb->query()
#4 /wp-includes/class-wp-query.php(3034): wpdb->get_results()
#5 /wp-includes/class-wp-query.php(3465): WP_Query->get_posts()
#6 /wp-includes/post.php(2153): WP_Query->query()
#7 /wp-content/plugins/woo-manage-fraud-orders/includes/class-wmfo-track-fraud-attempts.php(210): get_posts()
#8 /wp-content/plugins/woo-manage-fraud-orders/includes/class-wmfo-track-fraud-attempts.php(108): WMFO_Track_Customers::manage_blacklisted_customers()
#9 /wp-includes/class-wp-hook.php(292): WMFO_Track_Customers::manage_blacklisted_customers_checkout()
#10 /wp-includes/class-wp-hook.php(316): WP_Hook->apply_filters()
#11 /wp-includes/plugin.php(484): WP_Hook->do_action()
#12 wp-content/plugins/woocommerce/includes/class-wc-checkout.php(878): do_action()
#13 /wp-content/plugins/woocommerce/includes/class-wc-checkout.php(1152): WC_Checkout->validate_checkout()
#14 /wp-content/plugins/woocommerce-gateway-paypal-express-checkout/includes/class-wc-gateway-ppec-cart-handler.php(171): WC_Checkout->process_checkout()
#15 /wp-includes/class-wp-hook.php(292): WC_Gateway_PPEC_Cart_Handler->wc_ajax_start_checkout()
#16 /wp-includes/class-wp-hook.php(316): WP_Hook->apply_filters()
#17 /wp-includes/plugin.php(484): WP_Hook->do_action()
#18 /wp-content/plugins/woocommerce/includes/class-wc-ajax.php(90): do_action()
#19 /wp-includes/class-wp-hook.php(292): WC_AJAX::do_wc_ajax()
#20 /wp-includes/class-wp-hook.php(316): WP_Hook->apply_filters()
#21 /wp-includes/plugin.php(484): WP_Hook->do_action()
#22 /public_html/wp-includes/template-loader.php(13): do_action()
#23 /public_html/wp-blog-header.php(19): require_once('/home/517141.cl...')
#24 /public_html/index.php(17): require('/home/517141.cl...')
#25 {main}
  thrown in /public_html/wp-includes/wp-db.php on line 2056

Woo Manage Fraud Orders 2.0.0
WooCommerce v5.3.0
WC PayPal Checkout Gateway v2.1.1
WC Stripe Gateway v5.2.0
Wordpress v5.7.2