I use Kinsta hosting, and it seems not to use load balancer.
When I tested two export buttons today, for both the “Export without progress bar” and “Export” buttons, I saw the Error notice below but no PHP warning :
Notice: Undefined variable: dp in /wp-content/plugins/woo-order-export-lite/classes/core/class-wc-order-export-engine.php(350) : eval()’d code on line 3
And actually, I just found I got three other warnings simultaneously, and it did not happen again today.
Warning: current() expects parameter 1 to be array, null given in /www/leaderkid_808/public/wp-content/plugins/woo-order-export-lite/classes/formats/storage/class-woe-formatter-storage-summary-session.php on line 82
Warning: Invalid argument supplied for foreach() in /wp-content/plugins/woo-order-export-lite/classes/formats/class-woe-formatter-xls.php on line 318
Warning: Invalid argument supplied for foreach() in /wp-content/plugins/woo-order-export-lite/classes/formats/class-woe-formatter-xls.php on line 282
Warning: reset() expects parameter 1 to be array, null given in /wp-content/plugins/woo-order-export-lite/classes/formats/storage/class-woe-formatter-storage-summary-session.php on line 78`