Why can't I exclude a term ID from either get_terms or WP_Term_query?

Question

I have a custom post tipe ("artigo"), and this CPT has a registered taxonomy ("artigo_eixo"), with 3 registered terms in it.

I want to show, in that page, a sidebar listing all terms, except the current term, in the page that lists all posts with that term (http://localhost/mytaxonomy/current_term/)

However, I can't exclude the current term from the query.

I'm trying to get a list of taxonomy terms, but exclude a certain term from this list. I'm trying to follow the codex examples, but I'm having no success, using either get_terms() or WP_Term_query().

There are 3 terms and the IDs are 13,14,15. There are no posts or CPT items with those IDs.

I just tested get_queried_object_id() and it seems to be returning the proper term IDs of the term being shown -- that is, if I am viewing the URL of the term with ID 13, the function returns 13, and so on.

It also doesn't work using hardcoded values, be it a string, an integer, or an array of any of those types. Neither won't work:

'exclude' => 14
'exclude' => '14'
'exclude' => array(14)
'exclude' => array('14')

There are no errors displayed by PHP or the WP debug log.

get_terms

if (is_tax( 'artigo_eixo' )) {

    $current_eixo = get_queried_object_id();

    $args = array(
        'taxonomy' => 'artigo_eixo',
        'exclude' => $current_eixo
    );

    $eixos = get_terms( $args );

WP_Term_query

if (is_tax( 'artigo_eixo' )) {

    $current_eixo = get_queried_object_id();

    $args = array(
        'taxonomy' => array('artigo_eixo'),
        'exclude' => $current_eixo
    );

    $eixos = new WP_Term_Query( $args );
    $eixos = $eixos->terms;

Answer 1

Turns out there was a function hooking the filter list_terms_exclusions, and the return was inside a logically faulty conditional. I fixed it and now the term query exclusion works as intended.

Answer 2

Possible reason: get_queried_object_id() returns int, whereas exclude parameter uses array or string of comma separated ids.

First make sure you are getting right value in $current_eixo, and then try putting it in array and using that array as parameter.

'exclude' => array($current_eixo)

Although not sure if this is the problem in your case, give it a try.