I have been searching this a lot, but everything I do, does not seem to work, I tried,
cat: wolf; category desc
cat: wolf; sort category desc
$query->setQuery("cat: wolf")->sort("category desc");
I cannot sort the results, I have no idea what to do.
Sorting doesn’t work well on multivalued and tokenized fields.
Documentation
Use string as the field type (or KeywordTokenizer with lowercase filters and ascii filters applied) and copy the category field into the new field.