There is no need to add shortcode separately in shop / category page .
Enabling “Show Stock Status in Shop Page” option in woo-custom-stock-status settings page will automatically add custom stock status in shop and category page.
Shortcode only works when it is placed in product page or passing product_id argument along with the shortcode . For example [woo_custom_stock_status product_id=”1234″]
So, If you are using shortcode [woo_custom_stock_status] in shop / category page it will not work.
Please check if you have enabled the “Show Stock Status in Shop Page” option in custom stock status settings page?
Also check if you’re using current version of woo-custom-stock-status plugin ?
If you are still facing that issue, please send us a screenshot of your custom stock status settings page. also provide your site link to check the issue.
https://drive.google.com/file/d/19A_-sXNmlsyewpXT2wcxWnXE_nxljwB7/view?usp=drivesdk
Thank you.