Screen goes black and stops loading on mobile after scrolling so far down the page

I’ve recently taken on the CMS and uploading new case studies for our design agencies website. But I’ve noticed an issue on mobile, it’s fine when previewing in design mode but when viewing it on mobile, the site loads fine, but as you begin to scroll down, it gets so far and then goes black and appears to stop loading.

I’m quite new to this and am no web developer so any help and advice would be much appreciated.

Here’s a couple of links to pages that show the mentioned issue…

Thanks,
Joe.