Category entries

I already tried to add to functions.php the following codes:

add_filter('pre_get_posts', 'query_post_type');
function query_post_type($query) {
 if(is_category() || is_tag()) {
   $post_type = get_query_var('post_type');
    if($post_type)
        $post_type = $post_type;
    else
        $post_type = array('post','review');
   $query->set('post_type',$post_type);
    return $query;
   }
}

and

add_action( 'pre_get_posts', function ( $q )
{
    if (    !is_admin() // Only target front end queries
         && $q->is_main_query() // Only target the main query
         && $q->is_category() // Only target category archives
    ) {
        $q->set( 'post_type', ['post', 'review'] ); // Adjust as needed
    }
});

It didn't work.

Hmm, that's strange.

What are your permalinks set to in "Settings > Permalinks"?

Can you deactivate your custom functions, then re-save the permalink settings?

I forgot to change the permalinks and it was set to Date and time. Now it's set to Post name.
What do you mean by Custom functions?

Meanwhile I found a solution via a very old plugin: Custom posts type archive (https://wordpress.org/plugins/custom-post-type-taxonomy-archives/), like 7 years old. It did the trick. :)

The custom functions you pasted in your reply above.

Something must be interfering with the permalinks, as /category/name is a typical WP permalink structure. Perhaps try deactivating your other plugins/custom functions and then re-add them one by one to see if it's a plugin issue.

I deactivated all the plugins, reactivated one by one, and nothing happen. I'm pretty happy that it works, now I can sleep at night. :) If this is something that you'll like to check for you, I have no problem sending you the pass to check some things.

It's all working as it should now?

Yes. Everything's perfect.

Awesome :)