Multiple [display-posts] shortcodes on 1 page

Is there any way to improve loading speed on the page, where we have 10 [display-posts] shortcodes? We have a 5-8 seconds delay before page even starts to show up. It loads fine on pages with just 1 shortcode or if we remove the section with shortcodes. We use Autoptimize and object caching on our hosting, but maybe the plugin’s code itself can be optimized? Please give me some clues, thanks in advance