I know questions on this subject have been asked before. But I'm stuck and cannot find a way out.

I am using Ajax to load external information to my site. Initially all the information was loaded at once, but because of the large amount of data Ajax became a necessity.

The information is accessed from an external CMS, using a plugin developed by a 3rd party.

In the Ajax I have to use the plugin's `do_shortcode`. But it fails. No results are returned. When it is directly put in a page template's code it works flawlessly.

I have used the best practices I found to create the Ajax communication (i.e., use `wp_ajax` and `wp_ajax_nopriv` for the callbacks, registering, enqueueing, and localization of JS scripts). 

I tested the Ajax connection and I can send messages back and forth. But as stated, the shortcode is the one thing that always fails. 

I haven't been able to reach to the plugin developer. So I'm asking if there are any other things I should be aware of when trying to use shortcodes with wp_ajax.

Thanks in advance.