Wordpress API在api中缺少缩略图

Question

I have a problem with translated blog posts and wordpress api.

The attachment array is empty, it is filled only in the english version. Any hints?

English translation:

attachments":[{"id":11896,"url":"http:\/\/www.testblog.com\/wp-content\/uploads\/2017\/02\/Blog.jpg","slug":"blog-the-history","title":"Blog - The History","description":"","caption":"","parent":11895,"mime_type":"image\/jpeg","images":[]}]

German translation:

"attachments":[],"comment_count":0,"comment_status":"open","thumbnail":null,"custom_fields":{"blog_quote_author":[""],"blog_quote_text":[""],"blog_thumbnail":["11976"]},"thumbnail_size":"thumbnail","thumbnail_images":[]}

Wordpress Version: 4.7.2
WPML Plugin

Any help appreciated.