Does this plug in disable wordpress re-ordering posts by date

If the plugin Autosort is turned on, this is an expected behavior, you should set it off and add the ‘orderby’ => ‘menu_order’ to the queries where the order is required to apply. For more details see this topic https://ww.wp.xz.cn/support/topic/post-type-order-stops-random-header-image-showing/

Or you can consider the Advanced Post Types Order which includes conditionals to narrow down the order appliance to a specific url/urls.

Thanks