Thank you, perfect.
I found the issue. Somehow when fetching the posts the “post_type” => “any” argument was simply ignored by wordpress and completely removed any results from the array. I had to make a correction to the plugin code to fix that. I will include this in the next upcoming release for sure.
For reference the file I changed is: wp-content/plugins/ajax-search-pro/includes/classes/Search/SearchIndex.php