Hello,
1.) Taxonomy name change:-
File Name: taxonomies.php
File Path: plugins\dzcore\includes\helpers
check:
2.) Custom Post Type name change:-
File Name: post_types.php
File Path: plugins\dzcore\includes\resource
Find the last slug and change it with a new slug, in the theme and the dzcore plugin
You must run a function once whenever you change the taxonomy or CPT name.
flush_rewrite_rules()
Thanks