Exclude post ids not working

Hi

I have used the CRP shortcode on my template. It is all working really well, but I can’t exclude posts so that the plugin doesn’t display on certain pages.
I’ve tried on the page itself – checking the checkbox ‘Disable Related Posts display’ at the bottom of the page in admin.
I’ve tried adding a post id in the plugin Exclusion settings – Exclude display on these posts in admin.
And I’ve tried adding it in the shortcode [crp exclude_post_ids=’12’]

But I still see Related Posts listed at the bottom of my page.

Is this a bug? or should I be doing something else?

(I haven’t sent a link as the site is still in development and don’t want to publish it publicly)

Thanks!