Deleted featured images added as carrousel image in page

I’m no sure if this is an Aqua Theme issue or a WP one but the thing is: if I remove a featured image in a service page, for example, and I add a new one. The old one is not featured any longer but it is still shown in some kind of gallery/carrousel when the page is being shown. How can I remove completly that image from the page and manage that carrousel?

Thank you!