the related post check for related tag first, if did not find one, it will grab posts from same category.
it working fine in my end.
@danielaniculi Have you enabled related posts? Go to APPEARANCE, then CUSTOMIZE, then GENERAL. Select POSTS and then select ENABLE under ENABLE RELATED POSTS.
Choose how many related post will be displayed under CHOOSE RELATED COUNT. I selected 6 and 6 related posts are displayed on each post.
Thank you for your answers. It seems that related posts were not dispalyed because of insufficient tags. I am using another plugin now and after I updated my tags, all it is fine.
