Hello James,
Thank you for using our theme. Have you purchased one theme and try to use it on more than one website? If so, we only provide the support for one theme on one site. Please purchase another theme and post your question.
In the above question, you want to hide the featured image on single page, or archive page or other specific location or you want to hide only the default image only? If no featured image is set, you don’t want to show the default image?
If so, go to appearance > customize > extra options and custom no images and remove all the images and save it. Or if you want to hide the featured image on single page, you can find the options inside the layout options on the customizer.
Hope, this will solve your problems.
Regards,
Acme Supports