Our developers checked the issue.
We found that problem caused by the Embrulho de presente woocommerce plugin. This plugin adds the additional query to filter product by the Embrulho presente category and only after that applies the filter by brand in that category https://prnt.sc/u6wt0z
So, contact plugin author to sort our why they do this or if you want we can additionally customize child theme to use OR condition in the brand filter widget instead of the AND.
