gallery shows all images

I’m using the most up to date catch box with a child theme using a style.css

Hi I’ve added a gallery of 6 images. on clicking the first it takes me to a page with the image(regardless of image or attachement page settings) and on clicking the ‘next’ it takes me through all the images on the site. I’ve switched off any other plugins I’m using(not many) and cleared caches etc but can’t seem to get get it to work. Any ideas would be appreciated!

Thanks in advance.