Hi John
Thanks for posting. I should have posted here a little earlier. I also posted this to WordPress yesterday and got a resolution. I think there is a bug in WordPress which is evident when comparing custom fields and custom taxonomies that contain an apostrophe:
https://wordpress.org/support/topic/wp_query-custom-taxonomy-custom-field-comparison/#post-8806020
Applying the code from the above thread to the WordPress core (I know … but it makes sense) fixed my issue alongside wrapping the return I get from an ACF field in html_entity_decode before comparing it with my custom taxonomy.
Once again, thank you.
Regards
Mike
So … the page has converted every instance of ' ;
in my post to an apostrophe.