Hi there,
Sorry for the trouble. I will try to answer your questions one by one.
1. Its quite possible that your theme css conflicting ours or the the miss managing of the points mentioned below causing this issue.
We have tested on the fresh WordPress installation and everything worked fine.
2. The ‘set size: thumbnail’ gets value of default gallery image thumbnail size which is 150×150. If you see its not visible then probably the size is altered in the theme itself.
3. post-thumbnail option works if post-thumbnails is enabled in your current theme and the values set using this method:
set_post_thumbnail_size( 50, 50 );
50 pixels wide by 50 pixels tall
You can see large thumbnails because the size set by the theme is large itself, and you can only overwrite it in your theme files.
We also checked the link you provided and found Related Posts are disabled.
-
This reply was modified 5 years, 9 months ago by
Asad Shahbaz.