WP_Query – multiple orderby with a rand field, doesn’t work

The short answer is “you can’t do that.” Take a look at the Codex.

When using orderby as an array the value can either be ASC or DESC. If you want to set rand you would do so as a key only. That being said, ordering by random will override any other orders, so you won’t really get a benefit from ordering by tipo_prodotto_clause first.

'order' => 'ASC',  
'orderby' => 'rand',

Also make sure you take note of the required context for orderby rand:

Random order. You can also use ‘RAND(x)’ where ‘x’ is an integer seed
value. Note an “order” parameter needs to be present for “orderby”
rand to work.

A piece of advice: ordering randomly is highly discouraged. The query does not perform well in mysql and has the potential to break caching on a site for every request or not appear to work if caching is less flexible. In fact, WP Engine has banned its usage by default. Be careful using this. It’s usually better to find an alternative solution.