Jetpack 'Related Posts' no longer working

Hello, I recently customised the settings for Jetpack, Related Posts, by using the menu accessed from Plugins, Settings. As I finished my changes I noticed the text, "You can now also configure related posts in the Customizer. Try it out!" So I decided to try it out. I changed ONE thing. I changed the "Text to use as Headline" from "Related" to "Related Posts:" and clicked "Save & Publish". Now Jetpack is NOT showing ANY related post information. And I cannot get it to show related posts again. The theme I am using is Catch Evolution. An example post where it is not working is http://thechurning.net/a-book-which-should-be-on-every-change-makers-bookshelf/ Please help me get Related Posts working again. Thank you. Finn Jackson