Opencart_2.3.0.2_Order Status Configuration in Admin UI_For Paypal Standard Payment Module

Hi, we operate an ecommerce site on the Opencart platform, version 1.5.5.1. We have upgraded it to Opencart version 2.3.0.2, (cloned, then parked on a subdomain and then upgraded) and have found an issue whereby when an order is placed, the stock subtraction is not occurring as it did in our old 1.5.5.1instance. This issue is discussed in the Opencart forums. it is a simple issue that only needs UI configuration, within the admin console. it is a matter of knowing which tickboxes to use within the Order Status window... to work correctly and in conjunction with the order status settings in the paypal standard sales module. So this job isn't really a coding issue as far as I can tell, but more of a configuration matter in the admin UI area. So currently with the settings as used in our 1.5.5.1 instance.. on our new 2.3.0.3 version of the site, orders are not having stock subtract for the sold item. If I follow some of the settings advised in the very unclear opencart forum posts, when we set the order to shipped, the item that is sold is added back into stock... instead of subtracting. so each time we sell an item the stock levels wont be going down, and will eventually lead to a customer ordering an item that has no stock left. I was recommended to post this job on freelancer.com... even though its not necessarily a PHP code issue. But the webmaster who was trying to help me but couldn't as they don't know opencart, encouraged me to try posting here because of opencart's use of PHP, and that for a PHP dev familiar with opencart this might be a simple issue.