category show all does not show all?

Normally, if you have a product in a sub category, then show all function of parent category should display all item under that parent category. But Opencart does not.
For Opencart to show all items you need to add the product to parent category as well. If you several level of subcategory then is very difficult to manage since you need to add the product to all the categories in each level.

Try this
https://www.opencart.com/index.php?rout ... n_id=30830

It doesn't work for Opencart 3? I tried to put the code in the file but doesn't work.

Ok, all sorted is working now