I wanted to report a bug I have found in this plugin. It’s a very useful plugin, but unforcedly it has some bugs in it. Sometimes in category pages, even when the product is out of stock, the product still remains in the middle of the list. I have changed the quantity of the product to one then returned to zero but it did not work.
After some test, I found out that if I relate a product to more than one category, the product would not be moved in all of them. To put it better when a product has more than one category, it dose not reposition the out of stock product to the end of the list.
Please check this issue and if possible update this plugin.