I'm using Kerygma Theme from Organized Themes but no extra media plugins - though the Kerygma theme is fully responsive and images are resized on the fly - so whether it has something to do with that I don't know.
I have another site that runs TwentyFifteen theme that also resizes images on the fly, if I get chance later I might try to see if the images break on that site if I enable the 'Disable Code Execution for Uploads directory' in Wordfence.