Easyblog Tag Autofill not working

My customer has reported that tag autofill has not worked for a while. Sure, when I test it lets the icon "thinks" but returns no results. I do not see any config options for this, I am using the JCE editor for the blog not the built-in composer but a quick test on the test site did not show any difference using the block editor. I do not seem to have any errors in the logs or script errors on the page.
What should I be looking to check things are configured correctly?