I'm using the Jupiter theme version 5.1.8 with WordPress version 4.6.
When I preview a single post, the thumbnails displayed by the Jupiter theme's Recent Posts widget are all repeats of the current page's thumbnail. They are not displaying the thumbnails of the recent posts, as they should. I have noticed that the edit-post preview button results in a redirect URL with a
_thumbnail_id parameter. If I remove that parameter, then the proper thumbnails are displayed. Also, when I view the post with the permalink URL, then it looks OK. The Jupiter support person says that this is a bug in WordPress. Their quotes below:
It appears to be a bug in WordPress itself, the get_post_meta() function in particular returns the same _thumbnail_id when used in the conditions you specified in your ticket.
This problem occurs in the Twenty Sixteen 1.6 theme ( with the plugins Recent Posts Widget Extended and Recent Posts Widget With Thumbnails installed ) when previewing posts with the _thumbnail_id parameter set.
Has anyone else noticed this problem?