Hi, you looked at it today, right?
Last night I deactivated all plugins – und it worked.
Then I reactivated them – did not work.
Then I deactivated those only that I thought to be suspicious.
And here is the result: It’s Jetpack.
Jetpack activated: Newest post (in this case: Only post after installation) doesn’t show the featured image.
Jetpack deactivated: Everything is fine.
Which is fairly okay because most design and function options Jetpack offers are included in Enfold and look even better within the theme.
All I am missing at the moment are the statistics.
Probably you’ll be able to check for conflicting code within Jetpack and Enfold.

Best,
Christoph