First of all, thank you for your continued help. I really appreciate it.
I tried the code you suggested, but haven’t yet solved either of the issues. I feel like we’re getting closer to finding the issue.
The cs_industry is a taxonomy relating to the custom post type “case study”. And the variable $relatedCat does give a number (e.g. 1079).
When I print_r($args), I get:
Array ( [posts_per_page] => 3 [post_type] => case_study [meta_query] => Array ( [0] => Array ( [key] => cs_industry [value] => "1079" [compare] => LIKE ) ) [orderby] => DESC )