Why doesn't orderby="rand" work in woocomerce?

Question

WordPress

A very strange thing is happening

[recent_products orderby="rand" per_page="8"]
. This code displays the last added products, in the amount of 8 pcs and randomly.
Everything works fine, the goods change
Now we need to display the goods by attribute also randomly

[product_attribute per_page="8" orderby="rand" attribute="brand" filter="Omnilux" ]

I display in this way, it displays everything as it should, but orderby="rand" does not work. The products
are displayed constantly the same, although this brand has about 500 products.

What am I doing wrong? I tried everything in the same way to start through the shortcode [products] does not randomize.

In general, does the sequence of values ​​affect the work of the shortcode?