Hiya,
Sure – do note that the issue is not currently visible on the website, as the shop is live.
I have taken a screenshot, which can be seen here: https://pasteboard.co/IwUWuG2.png
In this, you can cleary see 3 empty blank spaces after the first product. That is because the next 3 items in the category are marked on my end as "not in stock".
So basically, all I need is for the AT Woocommerce Products widget to ignore products that are not in stock, and then everything will work perfectly.