Previous/Next buttons only same category

I’ve read all of the posts about the previous/next arrows on portfolio items not showing only items from the same category but I can’t get them to work. I’m using a child theme and the following in functions.php

if(!function_exists(‘avia_post_nav’))
{
function avia_post_nav($same_category = true, $taxonomy = ‘category’)
{
global $wp_version;
$settings = array();
$settings[‘same_category’] = $same_category;
$settings[‘excluded_terms’] = ”;
$settings[‘wpversion’] = $wp_version;

//dont display if a fullscreen slider is available since they overlap
if((class_exists(‘avia_sc_layerslider’) && !empty(avia_sc_layerslider::$slide_count)) ||
class_exists(‘avia_sc_slider_full’) && !empty(avia_sc_slider_full::$slide_count) ) $settings[‘is_fullwidth’] = true;

$settings[‘type’] = get_post_type();
$settings[‘taxonomy’] = ($settings[‘type’] == ‘portfolio’) ? ‘portfolio_entries’ : $taxonomy;

if(!is_singular() || is_post_type_hierarchical($settings[‘type’])) $settings[‘is_hierarchical’] = true;
if($settings[‘type’] === ‘topic’ || $settings[‘type’] === ‘reply’) $settings[‘is_bbpress’] = true;

$settings = apply_filters(‘avia_post_nav_settings’, $settings);
if(!empty($settings[‘is_bbpress’]) || !empty($settings[‘is_hierarchical’]) || !empty($settings[‘is_fullwidth’])) return;

if(version_compare($settings[‘wpversion’], ‘3.8’, ‘>=’ ))
{
$entries[‘next’] = get_previous_post($settings[‘same_category’], $settings[‘excluded_terms’], $settings[‘taxonomy’]);
$entries[‘prev’] = get_next_post($settings[‘same_category’], $settings[‘excluded_terms’], $settings[‘taxonomy’]);
}
else
{
$entries[‘next’] = get_previous_post($settings[‘same_category’]);
$entries[‘prev’] = get_next_post($settings[‘same_category’]);
}

$entries = apply_filters(‘avia_post_nav_entries’, $entries, $settings);
$output = “”;

foreach ($entries as $key => $entry)
{
if(empty($entry)) continue;
$the_title = isset($entry->av_custom_title) ? $entry->av_custom_title : avia_backend_truncate(get_the_title($entry->ID),75,” “);
$link = isset($entry->av_custom_link) ? $entry->av_custom_link : get_permalink($entry->ID);
$image = isset($entry->av_custom_image) ? $entry->av_custom_image : get_the_post_thumbnail($entry->ID, ‘thumbnail’);

$tc1 = $tc2 = “”;
$class = $image ? “with-image” : “without-image”;

$output .= ““;
$output .= ” <span class=’label iconfont’ “.av_icon_string($key).”></span>”;
$output .= ” <span class=’entry-info-wrap’>”;
$output .= ” <span class=’entry-info’>”;
$tc1 = ” <span class=’entry-title’>{$the_title}</span>”;
if($image) $tc2 = ” <span class=’entry-image’>{$image}</span>”;
$output .= $key == ‘prev’ ? $tc1.$tc2 : $tc2.$tc1;
$output .= ” </span>”;
$output .= ” </span>”;
$output .= ““;
}
return $output;
}
}

But I’m still getting all portfolio items, not just ones in the same category.