[Ten]

Finally It's working on 4.0.17.

That's what I had to do:

- It wasn't working with the first indications, and I could not change in the database what lachild said, because my version hasn't a field 'variants' in xcart_config.

So, in /admin/configuration.php:

Around line 143:

    $products_orderby = array(
        "productcode"     => func_get_langvar_by_name("lbl_sku"),
        "title"         => func_get_langvar_by_name("lbl_product"),
        "orderby"         => func_get_langvar_by_name("lbl_default"),
        "price"         => func_get_langvar_by_name("lbl_price")

Before "productcode", add

"add_date"     => func_get_langvar_by_name("lbl_date"),

And it's working very well, and I can change the order from the admin/General Settings/Appearance/ Select the order...

Hope this help!