Ajax URL is incorrect for custom post type

With Ajax enabled, the [yasr_visitor_votes] shortcode has an empty data-cpt attribute in the generated HTML, causing the URL for the WordPress API to be incorrect and return a 404 error. The API URL specifies ‘posts’ instead of the name of the custom post type.

I’ve created a fresh WordPress 5.6.1 install with no plugins other than CPT UI and YASR 2.6.1.

The request that fails has ‘posts’ in the URL and is: https://<site>/wp-json/wp/v2/posts/112?_fields=yasr_visitor_votes&_wpnonce=62077aa643

The (manually created) request that succeeds has the custom post type name in the URL and is: https://<site>/wp-json/wp/v2/<cpt name>/112?_fields=yasr_visitor_votes&_wpnonce=62077aa643

The URL portion in question is generated in yasr_front.js:
let cpt = yasrRaterVVInDom.item(i).getAttribute(‘data-cpt’);

The generated HTML has an empty ‘data-cpt’ attribute:

<!–Yasr Visitor Votes Shortcode–><div id=’yasr_visitor_votes_747′ class=’yasr-visitor-votes’><div class=”yasr-custom-text-vv-before yasr-custom-text-vv-before-747″>Click to rate this post!</div><div id=’yasr-visitor-votes-rater-f36c540a449a0′
class=’yasr-rater-stars-vv’
data-rater-postid=’747′
data-rating=’4.4′
data-rater-starsize=’32’
data-rater-readonly=’false’
data-rater-nonce=’fd37a17db7′
data-issingular=’true’
data-cpt=”>
</div>

This HTML is generated by YasrVisitorVotes.php:

$this->shortcode_html .= “<div id=’$htmlid’
class=’yasr-rater-stars-vv’
data-rater-postid=’$this->post_id’
data-rating=’$average_rating’
data-rater-starsize='”.$this->starSize().”‘
data-rater-readonly=’$this->readonly’
data-rater-nonce=’$this->ajax_nonce_visitor’
data-issingular=’$this->is_singular’
data-cpt=’$this->post_type’>
</div>”;

The ‘post_type’ property is filled in with this code (YasrShortcode.php, line 69):

$this->post_type = YasrCustomPostTypes::returnBaseUrl($this->post_id);

And the returnBaseUrl function is as follows (YasrCustomPostTypes.php, line 105):

public static function returnBaseUrl($post_id=false) {
if($post_id === false || !is_int($post_id)) {
$post_id = get_the_ID();
}
$post_type_object = get_post_type_object(get_post_type($post_id));
//if get_post_type_object fails for some reason, return ‘posts’
if($post_type_object === null) {
return ‘posts’;
}
return $post_type_object->rest_base;
}

At this point it starts calling the WordPress API.

Thank you!