So it appears your site having difficulty loading category products. You might want to enable Web Page Dumper via Dashboard -> Auto Amazon Links -> Tools -> HTTP Proxies.
As for the shortcode, from the image you posted, I can tell the shortcode is not converted to Amazon links and is left unchanged which usually occurs when the plugin is deactivated. If it is not the case, something must be preventing the plugin from processing shortcodes. Try to test a single shortcode in a test post and see if it makes a difference. If it doesn’t, try temporarily deactivating all the other plugins and switching to the default theme and see if the plugin shortcode gets converted. If it does, switch back to your theme and activate the plugins one by one. At some point, the problem will start occurring. Then you can tell which one causes the conflict.