BUG in Language Override for Products With Characteristics

-- url of the page with the problem -- : www.kapitisummerschool.co.nz
-- HikaShop version -- : 3.5.1
-- Joomla version -- : 3.8.12

For a school client I was able to change the language override for X_ITEMS_IN_STOCK from "%s item in stock" to "%s Spaces Available".
BUT this only works for products that do NOT have any characteristics added.

Here is a single product. Override works fine:
www.kapitisummerschool.co.nz/adult-cours.../category_pathway-12

But products with Characteristics still show: "%s item in stock", which is not acceptable for the client.
Example:
www.kapitisummerschool.co.nz/adult-cours.../category_pathway-15
Also, if you change the "Blacksmithing Course Dates" you will see that the wording changes from ITEMS to SPACES AVAILABLE depending on which course is selected.
I don't understand why this is changing.

I cannot find ANY additional language override for this in order to change it. I cannot find where the words are coming from.

Any ideas?

Thank you.

I found the language in en-GB.com_hikashop.ini

This language is different than the single product item: X_ITEM_IN_STOCK versus X_ITEMS_IN_STOCK

This file is not being seen by the override system.
Bug or design?

Yes, the firewall has blocked your country for too many hacking attempts.
As I found that other translation I got it to work now.

It is just odd that the second translation cannot be found using the Language Override.
I had to edit the file manually.